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1 


RESERVOIES 


FOR  IRRIGATION,  WATER-POWER, 

AND 

DOMESTIC  WATER-SUPPLY. 

WITH  ^  ^• 

AN  ACCOUNt  OF  VAEIOUS  TYPES  OF  DAMS  AND  THE 
METHODS  AND  PLANS  OF  THEIR  CONSTRUCTION. 

TOGETHER  WITH 

A  DTSCU88I0N  OF  THE  AVAILABLE  WATER-SUPPLY  FOR  IRRIGATION 
IN  VARIOUS  SECTIONS  OF  ARID  AMERICA;  TEE  DISTRIBUTION, 
APPLICATION,  AND    USE  OF  WATER;   THE  RAINFALL 
AND  RUN-OFF,  THE  EVAPORATION  FROM  RESEE- 
YOIRS;  THE  EFFECT  OF  SILT  UPON 
RESERVOIRS,  ETC. 


JAMES  DIX  SCHUYLEK, 

Member  American  Society  of  Civil  Engineers ;  Member  Institution  of  Civil 
Engineers,  London  ;  Member  Technical  Society  of  the  Pacific  Coast ; 
Member  Engineers  and  Architects'  Association  of  Southern 
California  ;  Member  Franklin  Institute  ;  Correspond- 
ing Member  American  Geographical  Society. 


FIRST  EDITION, 
FIKST  THOUSAND. 


NEW  YORK: 
JOHN  WILEY  &  SONS. 
Lokdok:  chapman  &  HALL,  Limited. 
1902. 


Copyright,  1901, 

BY 

JAMES  DIX  SCHUYLER. 


ROBERT  DRUMMOND,  PRINTER.  NEW  YORK. 


PREFACE. 


In  1896  the  author  was  requested  to  prepare  a  brief  descriptive  account 
of  such  of  the  principal  dams  and  reservoirs  as  had  come  under  his  observa- 
tion in  the  course  of  his  professional  practice  in  the  arid  region  of  the 
United  States,  for  publication  among  other  Water-supply  and  Irrigation 
Papers  issued  by  the  IT.  S.  Geological  Survey  for  the  general  information 
of  the  public  on  topics  of  popular  interest. 

In  compliance  with  this  request  a  paper  was  written  somewhat  hastily 
in  the  rare  leisure  intervals  of  a  busy  season,  which  was  printed  and  cir- 
culated as  a  portion  of  the  18th  Annual  Eeport  of  the  Geological  Survey, 
in  a  more  pretentious  form  than  had  been  anticipated  when  the  manu- 
script was  prepared.  The  rapidity  with  which  the  edition  of  the  paper  was 
exhausted  testified  to  the  existence  of  a  widespread  interest  in  the  subject 
of  water-storage  in  the  West,  and  a  general  demand  for  the  facts  regarding 
the  works  which  have  been  built  and  those  which  are  projected.  This  has 
encouraged  the  author  to  republish  the  paper  in  another  form,  revising  and 
adding  to  it  as  the  material  has  become  available.  The  work  does  not 
pretend  to  be  an  exhaustive  treatise  on  the  subject  of  dam-construction 
in  western  America,  nor  does  it  assume  to  cover  the  field  by  an  account  of 
all  the  important  dams  which  have  been  built.  It  is  chiefly  a  straightfor- 
ward description  of  those  works  with  which  the  author  has  become  familiar, 
either  as  a  consulting  engineer,  or  as  designer  and  constructor,  or  merely 
as  an  interested  observer  of  the  development  of  the  ideas  of  other  en- 
gineers. The  field  is  too  great  to  be  completely  covered  by  any  one  work, 
and  new  projects  are  developing  with  such  rapidity  as  to  render  the  task 
of  enumerating  them  all  quite  beyond  the  power  of  any  one  individual. 

For  what  it  may  be  worth  in  the  way  of  information  or  suggestion  to 
the  fellow  members  of  his  profession,  or  to  others  interested  in  the  storage 
of  water,  the  volume  is  modestly  presented,  craving  indulgence  for  all 
errors  of  omission  or  commission. 

James  D.  Schuylek. 

October,  1900, 


56272 


INTRODUCTION. 


The  development  of  a  water-supply  for  irrigation  in  the  arid  West 
sooner  or  later  reaches  a  stage  where  the  construction  of  storage-reservoirs, 
becomes  a  necessity.  If  the  stream  is  one  of  considerable  volume,  numer- 
ous irrigation-canals  will  be  constructed  from  it  at  all  convenient  points^ 
and  its  entire  normal  flow  will  be  utilized  before  the  impounding  of  flood- 
volumes  is  thought  of  as  a  possibility.  But  with  the  varying  seasons  there 
will  occasionally  come  a  year  when  the  best  of  streams  are  so  shrunken 
below  the  normal  as  to  limit  sharply  the  area  which  can  be  irrigated  from 
it,  and  emphasize  the  regret  that  some  means  had  not  been  provided  for 
holding  back  the  wealth  of  water  which  at  times  pours  into  the  sea  without 
benefit  to  any  one,  so  as  to  render  it  available  in  the  drier  part  of  the  year. 
Other  streams  there  are,  which  drain  very  large  districts  and  at  certain 
times  of  the  year  are  formidable  and  almost  impassable  rivers,  that  in  the 
summer  and  fall  are  dry  for  months  at  a  time.  If  these  sources  are  to  be 
rendered  servicable  ^storage-reservoirs  must  be  built  as  the  initial  step  in 
irrigation  development. 

All  streams,  except  they  be  regulated  by  nature  by  means  of  lakes  or 
subterranean  reservoirs,  are  subject  to  great  fluctuation.  It  is  the  function 
of  artificial  reservoirs  to  equalize  in  a  measure  these  variations  in  flow,  im- 
pounding the  floods  for  use  in  the  season  when  irrigation  is  necessary. 
Were  it  possible  to  conceive  of  a  stream  flowing  throughout  the  year  without 
change  in  volume,  such  a  stream  would  not  have  its  fullest  measure  of  use- 
fulness without  storage  of  the  water  flowing  during  the  period  of  the  year 
when  irrigation  is  not  needed. 

Inasmuch  as  the  total  available  water-supply  of  the  arid  region  is  vastly 
short  of  the  quantity  needed  for  irrigating  all  the  land  requiring  artificial 
watering,  it  is  evident  that,  under  every  condition  and  with  every  class  of 
stream,  storage-reservoirs  are  needed  to  develop  the  fullest  measure  of  use^ 
fulness  of  the  existing  supply. 

Unfortunately  it  is  beyond  the  possibility  of  hope  that  all  the  water 
flowing  can  be  stored  or  utilized.  There  is  such  a  wide  range  in  the  total 
run-off  of  every  stream  from  one  season  to  another  that  it  would  rarely  be 
possible  to  find  storage  capaicty  for  the  extremes  of  flow.    On  large  rivers 


INTRODUCTION^. 


the  nitio  botween  maxiniiiin  and  iriiiiiinurn  years  may  vary  as  12  to  1,  wliilo 
on  siiiallor  streams  the  total  flow  one  year  may  be  one  hundred  times  as 
much  as  that  of  the  next  year.  Hence  the  reservoirs  which  might  be  pro- 
vided to  catcli  all  the  How  of  average  years  would  occasionally  be  ovei-- 
whelmed  by  freshets  so  extraordinary  as  to  fill  them  several  times  over. 
This  condition  has  an  important  bearing  on  the  design  of  every  reservoir 
located  in  the  path  of  floods,  first,  in  emphasizing  the  necessity  for  provid- 
ing ample  spillway  capacity,  large  enough  to  carry  safely  the  greatest  possi- 
ble or  proba1)le  flow,  and,  second,  in  fixing  the  proportion  which  the 
capacity  of  tlie  reservoir  may  bear  to  the  total  annual  run-off  of  the  stream, 
so  as  to  minimize  the  ratio  of  silt  deposited  to  the  total  volume  of  water 
impounded.  It  may  be  accepted  as  true  that  the  destiny  of  every  reservoir 
is  to  be  fllle  I  with  silt  sooner  or  later.  If  a  reservoir  were  created  on  a 
stream  carrying  silt  to  the  extent  of  Ifo  of  its  volume  on  an  average 
(although  few  actually  carry  so  much  as  1^),  and  the  average  annual  flow 
of  the  stream  were,  for  an  extreme  example,  fifty  times  as  great  as  the 
capacity  of  the  reservoir,  the  latter  would  be  filled  and  become  unservice- 
able in  two  years,  assuming  that  the  greater  portion  of  the  silt  carried  was 
depositeJ  in  the  reservoir.  It  would  evidently,  therefore,  be  unprofitable 
to  construct  such  a  reservoir  unless  provision  were  made  for  an- immediate 
increase  in  height  of  dam,  for  diverting  the  river  around  the  reservoir, 
which  is  usually  impracticable,  or  for  sluicing  or  dredging  the  silt  from  the 
reservoir,  a  process  invoking  great  expense.  If,  on  the  other  hand,  the 
reservoir  capacity  was  made  great  enough  to  store  rather  more  than  the 
usual  average  flow  for  one  year,  the  period  of  usefulness  of  the  works  would 
*  be  vastly  increased,  and  the  consideration  of  the  problem  of  silt  disposal 
would-be  left  for  future  generations  to  solve. 

The  importance  of  reservoir-construction  and  water-storage  for  irriga- 
tion was  not  so  generally  recognized  in  the  arid  region  prior  to  about  the 
year  1885  as  it  has  been  subsequent  to  that  time,  and  it  is  only  within  a 
comparatively  recent  period  that  capital  has  been  extensively  enlisted  in 
such  works  except  for  the  storage  of  water  for  cities  and  towns.  With  a 
few  prominent  examples  of  successful  achievement  in  that  line  as  precedents, 
however,  the  subject  of  water-storage  has  awakened  wide-spread  attention, 
and  each  year  it  appears  to  be  attracting  deeper  public  interest.  Capital 
has  been  slow  to  undertake  the  largest  and  most  important  works  of  this 
character,  because  of  the  difficulty  of  realizing  immediate  returns  upon  the 
investment.  The  development  of  a  new  section  upon  which  water  is  but 
recently  introduced,  the  construction  of  distributing  canals,  ditches,  and 
pipes,  the  cultivation  of  the  land  and  the  planting  of  orchards— in  fact  the 
conversion  of  a  desert  to  a  condition  of  profitable  productiveness,  is  the  work 
of  time,  which  cannot  be  begun  until  the  irrigation-works  are  actually  com- 
pleted, and  when  begun  is  slow  of  full  development.    Meantime,  however, 


INTBOD  JJGTION, 


vii 


the  interest  accoant  accumulates,  and  often  is  so  far  in  excess  of  possible 
revenues  as  to  bring  discouragement,  and  sometimes  actual  bankruptcy, 
before  a  paying  basis  is  reached.  The  uncertainty  of  the  laws  of  the  differ- 
ent States  governing  water  rights  in  reservoirs,  the  difficulty  of  establishing 
fixed  rates  for  water  that  will  be  high  enough  to  afford  an  adequate  revenue 
to  the  capital  involved  and  low  enough  to  enable  the  farmer  to  pay  for  the 
water  he  requires  and  make  a  living  while  developing  his  farm,  and  the 
responsibilities  involved  in  the  risk  fiom  floods,  accidents,  and  dry  seasons, 
have  been  potent  in  deterring  capitalists  from  investing  in  the  business  of 
storing  and  selling  water,  per  se,  unless  it  were  coupled  with  the  ownership 
of  the  lands  to  be  irrigated,  or  with  the  domestic  supply  of  a  growing  town, 
or  with  the  possibilities  of  generating  water-power. 

The  recent  development  of  electrical  machinery,  by  which  power  may 
i  profitably  be  transmitted  long  distances  with  comparatively  small  loss,  has 
'  indirectly  benefited  the  irrigation  development  of  the  country  by  adding 
an  incentive  to  the  construction  of  storage-reservoirs  for  the  primary  and 
more  profitable  purpose  of  generating  power.  Many  reservoirs  are  being 
favorably  considered  by  capitalists  for  the  power  which  they  will  afford  that 
would  otherwise  be  regarded  as  comparatively  valueless  or  unprofitable 
investments  for  irrigation  alone.  As  the  great  bulk  of  precipitation  in  the 
arid  region  occurs  in  the  mountains,  where  it  increases  with  some  degree  of 
uniformity  with  every  foot  of  increased  altitude,  the  mountains  are  coming 
to  be  regarded  as  indispensable  to  the  wealth  of  the  country,  valuable  not 
only  for  their  precious  metals,  stone,  and  timber,  but  for  the  store  of  water 
which  they  are  able  to  supply  to  the  thirsty  plains  below.  The  mountains 
not  only  supply  the  water,  but  they  usually  afford  the  best  sites  for  reservoirs 
to  impound  it,  in  ancient  lake-beds,  and  high,  cool,  deep  valleys,  surrounded 
by  forests;  while  the  latter  fulfil  a  most  important  function  and  attain  a 
Yalue  far  higher  than  the  mere  commercial  one  to  be  derived  from  their 
lumber  and  firewood,  by  serving  to  retard  the  rapid  run-off  of  the  water- 
supply.  Forest  growth  is  of  primary  importance  in  the  preservation  of  the 
source  of  streams,  in  preventing  the  mountains  from  being  washed  down 
with  destructive  force  to  the  valleys  and  the  sea,  and  in  creating  natural 
reservoirs  on  every  square  mile  of  their  surface. 

That  storage-reservoirs  are  a  necessary  and  indispensable  adjunct  to 
irrigation  development,  as  well  as  to  the  utilization  of  power,  requires  no 
argument  to  prove.  That  they  will  continue  to  become  more  and  more 
necessary  to  our  Western  civilization  is  equally  sure  and  certain;  but  the 
signs  of  the  times  seem  to  point  to  the  inevitable  necessity  of  governmental 
control  in  their  construction,  ownership,  and  administration.  Those  which 
private  capital  may  undertake  should  only  be  permitted  to  be  erected  under 
the  most  rigid  governmental  supervision,  to  assure  their  absolute  safety. 
Many  reservoirs  are  needed  for  the  development  of  the  arid  regions  which 


viii  INTRODUCTJON. 

are  of  too  great  a  magaitade  to  be  undertaken  by  private  capital  or  organized 
individual  ellort.  In  every  other  country  such  works  are  undertaken  by 
the  national  government.  In  general  it  may  be  said  that  the  lands  which 
would  be  benefited  by  such  works  in  arid  America  belong  to  the  govern- 
ment. To  make  these  lands  productive  and  capable  of  sustaining  popula- 
tion, the  government  of  the  United  States  should  undertake  their  reclamation 
and  construct  and  administer  the  reservoirs.  That  such  a  policy  will  ere 
long  be  inaugurated  seems  inevitable.  The  purpose  of  this  work  is  ta 
familiarize  the  public  with  the  details  of  construction  and  the  general 
features  of  interest  appertaining  to  the  principal  reservoirs  constructed  or 
projected  in  the  Western  States  and  Territories  which  have  come  within  the. 
knowledge  or  observation  of  the  writer,  describing  in  a  popular  way  their 
characteristics,  their  water-supply,  the  results  accomplished  or  sought  ta 
be  accomplished  by  them,  and  the  methods  and  materials  employed  in  the^ 
construction  of  the  dams  which  form  them. 


TABLE  OF  CONTENTS. 


CHAPTER  I. 

Rock- FILL  Dams  

Various  types  of  rock-fill  dams  described. — The  Escondido  dam,  faced  with 
redwood  plank — the  first  rock-fill  dam  built  for  irrigation  storage. — Lower  Otay 
steel-core,  rock-fill  dam,  general  description  of  construction. — Morena  rock-fill 
dam,  with  concrete  facing. — Barrett  dam,  under  construction. — Upper  Otay  dam, 
projected  and  begun.— Chatsworth  Park  rock-fill,  with  concrete  and  masonry 
skin. — The  Pecos  Valley,  N.  M.,  type  of  rock-fill  dams,  with  earth  facing. — Quick- 
opening  spillway  gates.— Walnut  Grove  rock -fill  dam,  and  its  disasterous  failure. 
— East  Canyon  Creek  rock-fill  dam,  with  plate-steel  center-core.— South  Platte 
dam. — The  English  dam,  Cal.,  timber-crib  rock-fill.— The  Bowman  dam,  an  exist- 
ing example  of  earlier  rock-fill  construction. 

CHAPTER  II. 

Hydraulic-fill  Dams  

Principles  of  dam  construction  by  the  agency  of  water. — San  Leandro  and 
Temescal  dams,  supplying  Oakland,  Cal  ,  partially  built  by  thV hydraulic  method. 
— The  Tyler,  Texas,  hydraulic-fill  dam,  the  cheapest  on  record.  — La  Mesa,  Cal., 
hydraulic-fill  dam,  and  the  assorting  of  rock  and  earth  by  the  varying  velocities 
of  water. — The  Lake  Christine  hydraulic-fill  dam,  San  Joaquin  River,  Cal.,  in 
process  of  construction. — The  filling  of  high  trestles  with  earth  and  rock  embank- 
ment by  hydraulic  methods  on  the  Canadian  Pacific  and  Northern  Pacific  railways, 
as  illustrating  the  principles  of  hydraulic  dam  construction. —Hydraulic  construc- 
tion at  Seattle,  Tacoma,  and  elsewhere. 

CHAPTER  in. 

Masonry  Dams  w  

Elementary  principles  involved.— Curved  vs.  straight  masonry  dams.— The 
advantages  of  curvature  in  all  masonry  dams  as  a  safeguard  against  cracks  due  to 
extreme  changes  of  temperature.— The  old  Mission  dam,  erected  by  the  Jesuit 
Fathers  near  San  Diego,  Cal.,  one  of  the  first  structures  of  its  kind  in  America,— 
El  Molino  dam.— The  Sweetwater  dam,  its  original  design,  construction,  severe 
test  and  subsequent  enlargement  —The  silt  problem  in  the  Sweetwater  reservoir. 
—The  Heraet  dam  and  the  irrigation  of  land  from  Lake  Hemet  reservoir.— The 
Bear  Valley  dam,  the  slenderest  dam  of  its  height  in  the  world  — La  Grange 
dam,  the  highest  overflow  dam  in  America.— The  Folsom  dam,  Cal.,  erected  by 

ix 


1 


TABLE  OF  CONTENTS. 


PAOB 

convict  labor. — The  San  Mateo,  Cal.,  concrete  dam,  the  greatest  mass  of  concrete 
in  existence, — Run-off  of  streams  supplying  the  San  Mateo  and  adjacent  reser- 
voirs.— Pacoima  submerged  dam. — Agua  Fria  dam,  Ariz.,  and  the  limited  volume 
of  underflow  in  streams  shown  by  its  construction. — The  Seligman  dam. — The 
Williams  dam. — The  Walnut  Canyon  dam,  Ariz.,  and  the  phenomenal  leakage  of 
the  reservoir  behind  it. — The  Ash  Fork,  Ariz.,  steel  dam,  the  only  one  of  its  typo 
in  the  world. — The  Lynx  Creek  dam,  and  its  failure,  a  conspicuous  example  of 
how  dams  should  not  be  built. — Concrete  dams  at  Portland,  Oregon. — The  Basin 
Creek,  Mont.,  masonry  dam. — A  masonry  dam  under  640-ft.  head. — New  Croton 
dam.  New  York,  and  other  dams  of  the  New  York  City  water-supply  vv^orks. — 
Indian  Kiver  dam. — Cornell  University  dam  and  the  provision  made  for  con- 
traction cracks— Bridgeport  and  Wigwam  dams.  Conn. — The  Austin  dam  and  its 
recent  failure. — Masonry  dams  in  Guanajuato,  Mexico. — Foreign  dams  of  Spain, 
France,  Belgium,  Italy,  Wales,  Algiers,  Germany,  Egypt,  India,  China,  and 
Australia. 

CHAPTER  IV. 

Earthen  Dams   274 

Ancient  earth  dams  of  Ceylon  and  India,  of  enormous  dimensions. — Modern 
dams  of  India. — General  principles  to  be  observed  in  earth  dam  construction. — 
The  Valiejo  dam. — Cuyamaca  dam  and  reservoir  and  the  irrigation  system  sup- 
plied.— Merced  reservoir  dam.— Buena  Vista  Lake  dam. — Pilarcitos  and  San 
Andres  dams,  supplying  San  Francisco. — Cache  la  Poudre  dam. — Earth  dams 
erected  by  the  State  of  Colorado. — Doubtful  results  of  State  construction  of  stor- 
age-reservoirs. 

CHAPTER  V. 

Natural  Reservoirs  299 

The  Alpine  Reservoir,  Cal.,  formed  by  an  earthquake.— Twin  Lakes  Reservoir, 
Colo.— Larimer  and  Weld  natural  reservoir.— Marston  Lake,  supplying  Denver. — 
Loveland  basin. — The  Laramie  basin,  Wyo. — Lake  de  Smet,  Wyo. — Natural 
gravel-bed  storage-reservoirs  on  the  Los  Angeles,  San  Gabriel  and  Santa  Ana 
rivers,  in  Southern  California. 

CHAPTER  VL 

Projected  Reservoirs  314 

Reservoir  surveys  made  by  the  U.  S.  Geological  Survey,  tables  of  capacity  and 
area,  and  contour  maps  in  Appendix.— Government  surveys  in  Wyoming  and  Col- 
orado, reported  on  by  Col.  H.  M.  Chittenden,  Corps  of  Engrs.,  U.  S,  A.— Govern- 
ment reservoir  surveys  on  the  Gila  River,  Arizona,  to  provide  storage  water  for 
irrigation  on  the  Gila  River  Indian  Reservation.— The  San  Carlos,  Riverside,  and 
Buttes  sites.— The  Tonto  Basin  reservoir,  Ariz.,  and  the  projected  mammoth  dam 
of  masonry.— Proposed  reservoirs  on  Rio  Verde,  Arizona. — Projected  dam  in  Bear 
Canyon,  near  Tucson,  Arizona,  for  power  and  irrigation.— Proposed  dams  and 
reservoirs  on  the  Rio  Grande  in  New  Mexico  and  Texas. — The  Elephant  Butte 
masonry  dam.— Run-off  of  the  Rio  Grande  and  vs^ater- supply  available  for  irrigation. 
— Proposed  reservoirs  in  Texas.— Caimanche  Lake.— Nueces  reservoir.— Fria  River 
reservoirs.— Sand  Lake  reservoir. — Upper  Pecos  reservoir-sites  in  New  Mexico. — 


TABLE  OF  CONTENTS. 


xi 


Projected  dam  and  reservoir  on  Rock  Creek,  Nev.,  for  irrigation  in  the  Humboldt 
Valley. — Lost  Canyon,  Colo.,  natural  rock-fill  dam. — Projected  reservoirs  in  Cali- 
fornia,— The  Little  Bear  Valley  dam,  of  concrete,  in  process  of  construction  by  the 
Arrowhead  Eeservoir  Co. — Huston  Flat  reservoir-site,  and  its  projected  hydraulic- 
fill  dam. — Grass  Valley  reservoir-site. — The  projected  masonry  dam  at  Victor,  Cal. 
on  the  Mojave  River. — Projected  reservoirs  in  San  Diego  Co. — Proposed  reservoirs 
on  Kern  River,  Cal. — The  Manache  Meadows  site  and  the  project  of  the  Kern- 
Rand  Reservoir  and  Electric  Co.  for  power  utilization. — Kern  Lake  reservoir-site. — 
Big  Meadows. — Utilization  of  natural  lakes. — The  enterprise  of  the  Great  Plains 
Water  Co.  in  the  Arkansas  Valley,  Colo.,  in  the  storage  of  flood  waters  in  enor- 
mous natural  basins. 

APPENDIX. 

Containing  tables  of  reservoir  areas  and  capacities  of  selections  made  by  U.  S. 
Geological  Survey — tables  of  capacities  of  various  reservoirs  in  service — tables 
of  cost  of  reservoirs  per  acre-foot  of  reservoir  capacity,  etc   385 


I 


LIST  OF  ILLUSTEATIONS. 


PAGE 

1.  Map  of  Escondido  Irrigation  District  and  System  of  Works   3 

2.  Feeder  Canal  on  tlie  Side  of  Rodriguez  Mountain,  Escondido  Irrigation  District  3 

3.  Feeder  Conduit  of  Escondido  Irrigation  District  ^  g 

4.  Escondido  Irrigation  Dam,  looking  north,  showing  Spillway   7 

5.  Back  of  Escondido  Irrigation  District  Dam   9 

6.  Plans  and  Profiles  of  Escondido  Dam  ,   22 

7.  Details  of  Gate  of  Escondido  Dam,.  

8.  Pick-up  Weir  at  Head  of  Distributing  System  in  Escondido  Irrigation  District.  14 

9.  Contour  Map  of  Reservoir  of  Escondido  Irrigation  District   16 

10.  Construction  of  Facing  of  Escondido  Dam   jij* 

10a.  Escondido  (Cal.)  Rock-fill  Dam— Wooden  Lining  facing  page  18 

10^>.  Site  of  Dam,  South  Platte  Reservoir  Site— Narrowest  Part  facing  page  19 

11.  Masonry  Foundation  of  Lower  Otay  Dam  

116.'  i  ^^^^  (^^^'^  I^ock-fiU  Dam— Steel  Core  facing  pages  22,  34 

12.  Steel  Web-plate  and  Anchor-trench  at  West  End  of  Lower  Otay  Dam    23 

12a.  Otay  (Cal.)  Rock-fill  Dam— Steel  Core.  facing  page  25 

13.  Crest  of  Lower  Otay  Dam,  showing  Web-plate  of  Steel  embedded  in  Concrete. 

Dam  nearing  Completion  

14.  Map  of  Lower  Otay  Reservoir   26 

15.  Plans  of  Lower  Otay  Reservoir. ,  ,   28 

■  16.  Explosion  of  Great  Blast  at  Lower  Otay  Rock-fill  Dam   29 

17.  Barrett  Dam  

18.  Morena  Dam-site,  looking  Ea  t  ,   giy 

19.  Morena  Rock-fill  Dam  in  Process  of  Construction.    Showing  Top  of  Toe-wall 

above  the  Water-line   39 

"20.  Morena  Rock-fill  Dam,  showing  a  Portion  of  Toe- wall  under  Construction   40 

21.  Reservoirs  near  San  Diego,  California                                                            .  4^ 

22.  Upper  Otay  Dam,  Foundation  Masonry   42 

^3.  Sketch  of  Reconstruction  of  Chatsworth  Park  Rock-fill  Dam   44 

:24.  Castlewood  Dam,  Colorado  ;  Plan,  Sections,  and  Elevation   46 

:24a.  View  of  Castlewood  Dam,  Colorado,  during  Construction,  looking  North 

facing  page  4Q 

"346   View  of  Castlewood  Dam  and  Reservoir,  Colorado  .facing  page  47 

25.  Sketch-map  of  Dam  at  Head  of  Pecos  Canal   47 

:26.  Lake  Avalon  Dam.    Rock-fill  in  Process  of  Construction   48 

27.  Lake  Avalon  Dam,  Pecos  River,  New  Mexico.    Showing  the  Crest  of  Com- 

pleted Dam  and  Spillway  Discharging   49 

28.  Canal  Headgates,  Lake  Avalon  Dam     5q 

29.  Quick-opening  Gates  in  Spillway  of  Lake  Avalon  Reservoir,  Pecos  Valley,  New 

Mexico   ri 


xiv  LIST  OF  ILLUSTRATIONS. 


FIGURE  PAOa 

30.  Sections  of  Lake  Avalon  and  Lake  McMillan  Kock-fill  and  Earth  Dams,  Pecos 

Valley,  New  Mexico   51 

31.  Sketcb-niap  of  Pecos  Valley  Canals   ....  52 

32.  Map  of  Pecos  Valley,  New  Mexico,  showing  Location  of  Reservoirs  and  Canals  55 

33.  C'ross-section  and  Elevation  of  Walnut  Grove  Dam,  Arizona   59 

34  View  of  W^alnut  Grove  Dam,  Arizona  , . , ,  ,   60 

35.  East  Canyon  Creek  Dam,  Utah.    Rock-fill  with  Steel  Core   65 

36.  Balanced  Valve,  used  for  Reservoir  Outlet,  South  Platte  Rock-fill  Dam   68 

37.  South  Platte  Rock-fill  Dam.  View  of  False  Work  and  Bridge  over  the  Dam-site  69 
itla.  Site  of  Dam,  South  Plate  Reservoir  S.te — Above  .facing  page  71 

38.  Map  of  Reservoir  formed  by  Rock-fiil  Dam  on  South  Platte  River,  Colorado  ...  72 

38a.  Plan  and  Cross-section  of  the  Bowman  Dam  facing  page  74 

38^>.  Plan  and  Cross-section  of  the  Fordvce  Rock-fill  Dam,  California. .  .facing  page  75 

39.  Plans  and  Cross-sections  of  San  Leandro  and  Temescal  Dams   78 

40.  Hydraulic-fill  Dam  at  Tyler,  Texas,  showing  Delivery-pipe  supported  on  a 

Grade-line,  carrying  M^erial  to  Opposite  Side,  and  Spillway  Cut  made  by 

sluicing  the  Earth  into  Base  of  Dam   79 

41.  Hydraulic  Sluicing  for  building  Dam  at  Tyler,  Texas   81 

42.  Hydraulic-fill  Dam,  at  Tyler,  Texas,  in  Process  of  Construction   85 

43.  View  of  Fiaished  Dam  and  Wasteway  of  La  Mesa  Reservoir   87 

43a.  La  Mesa  (Cal.)  Dam  in  Course  of  Construction  by  the  Hydraulic  Process 

facing  page  84 

44.  La  Mesa  Reservoir.    Beginning  of  the  Construction  of  Hydraulic-fill  Dam. ... .  91 

45.  Details  of  Outlet-gate  and  "Well-culvert  of  La  Mesa  Dam   .  93 

46.  Construction  of  Hydraulic  Dam,  La  Mesa  Reservoir,  illustrating  the  Method  of 

Suspending  Pipes   95 

47.  Cross-section  of  La  Mesa  Dam   97 

48.  La  Mesa  Hydraulic- fill  Dam,  showing  Pipe  Discharging  Material  on  the  Dam. ,  98 
48<z.  View  of  Lake  Christine  Dam-site,  showing  Outlines  of  Hydraulic-fill  Dam 

f  acing  page  93 

486.  View  of  Lake  Christine  Dam-site,  San  Joaquin  River,  near  Fresno,  California, 

where  a  Hydraulic-fill  Dam  is  in  Process  of  Construction  .facing  page  99 

49  Hydraulic  Sluicing,  Canadian  Pacific  Railway.    View  of  Pit,  and  Hydraulic 

Giant  at  Work   101 

50.  Hydraulic  Fills,  partially  completed,  at  Mountain  Creek,  B.  C.,  Canadian  Pa- 

cific Railway..  107 

51.  Hydraulic  Filling  of  High  Trestle  at  Mountain  Creek,  B.  G.,  on  Canadian  Pa- 

cific Railway,  near  View  of  Dump   109 

53.  Northern  Pacific  Railway.    Bridge  190   Ill 

53.  Northern  Pacific  Railway.    Bridge  189,  Cascade  Mountains  113 

5*.  Northern  Pacific  Railway,  Hydraulic-fill  Construction.    View  in  Pit  showing 

Hydraulic  Giant  in  Action   113 

55  Northern  Pacific  Railway,  Bridge  184.    Hydraulic  Filling  in  Progress  114 

56.  Comparison  of  Profiles  of  Zola,  Sweetwater,  and  Bear  Valley  Dams   ....  120 

57.  Old  Mission  Dam,  near  San  Diego,  Cal.    The  First  Irrigation  Dam  built  in  the 

United  States   123 

58  Original  Sweetwater  Dam  as  completed  to  the  Sixty-foot  Contour  127 

59.  Elevations  and  Sections  of  Sweetwater  Dam   129 

60.  Face  of  Sweetwater  Dam  in  1899.    After  Two  Years  of  Drouth  130 

61.  Details  of  Tower  of  Sweetwater  Dam   133 

62.  Sweetwater  Dam  as  finished,  April,  1888   133 


LIST  OF  ILLUSTHATIONS. 


XV 


FIGURE  PAGE 

63.  Sweetwater  Dam  during  the  Great  Flood  of  January  17,  1895. o o, o  »  = «  134 
63a.  Sweetwater  (Cal.)  Masonry  Dam  .facing  page  135 

64.  Spillway  of  Sweetwater  Dam,  seen  from  Below   , ,  136 

65.  Sweetwater  Dam,  showing  New  Apron  of  Spillway  and  Protecting  Spur-walls 

on  Pipe-line  ,  Igg  ^ 

66.  Repairing  and  Increasing  the  Height  of  the  Parapet  of  Sweetwater  Dam  141 

67.  Plan  of  Sweetwater  Dam   145 

68.  Profile  and  Sectional  View  and  Plan  of  Waste  way  Tunnel,  Sweetwater  Dam...  145 

69.  Details  of  Sweetwater  Dam  146 

70.  Sweetwater  Dam,  showing  Head  of  Outlet  Tunnel  and  Spillway   147 

71.  Map  showing  Location  of  Lake  Hemet,  the  Main  Conduit,  and  Irrigated  Lands.  153 

72.  Hemet  Dam,  Riverside  County,  California   155 

73.  Hemet  Dam  as  finished,  showing  the  Spillway  Ridge  south  of  the  Dam   157 

74.  Contour  Map  of  the  Lake  Hemet  Reservoir.   159 

75.  Hemet  Dam,  Riverside  County,  California   160 

76.  Hemet  Dam  Construction  Plant   161 

76a.  Lake  Hemet  (Cal.)  Masonry  Dam  .facing  page  164 

77.  Cross-section  of  Bear  Valley  Dam   165 

78.  Plan  and  Elevation  of  Bear  Valley  Dam  , . . .  165 

79.  Bear  Valley  Dam,  looking  soutb,  toward  Spillway   167 

80.  Spillway  of  Bear  Valley  Dam,  with  Flashboard  Gates   169 

81.  Base  of  New  Rock-fill  Dam,  Below  the  Bear  Valley  Dam.  , ,  171 

83.  Map  of  Bear  Valley  Reservoir   l'j'5 

82a.  Plan  of  La  Grange  Dam,  California.   I77 

825.  Profile  of  La  Grange  Dam,  California  ,   I77 

88.  Upper  Face  of  La  Grange  Dam   l^g 

84.  Lower  Face  of  La  Grange  Dam   jij'g 

85.  La  Grange  Dam,  California,  during  Constuction— finishing  the  Crest   181 

86  ) 

grj,"  V  La  Grange  Dam,  California  _  Igj  jgg 

88.  La  Grange  Dam,  California,  during  Flood   183 

89.  Map  showing  Location  of  Folsom  Dam  and  the  Main  Canal   185 

90.  Plan,  Cross-section,  and  Elevation  of  W^eir  and  Headworks  of  Folsom  Canal. . .  186 

91.  American  River  Dam  at  Folsom   jg^ 

92.  Hydraulic  Jacks  for  raising  Shutter  on  Folsom  Dam   _  igg 

93.  View  of  Masonry  Dam  on  American  River,  California,  at  the  Folsom  State 

Prison,  showing  Canal  Head-gates   ;l9j 

94.  Plant  for  Mixing  and  Handling  Concrete  at  San  Mateo  Dam   I93 

95.  Construction  of  Intake  of  San  Mateo  Dam   *  295 

96.  Moulds  for  Concrete  Blocks,  San  Mateo  Dam  .*  "  197 

97.  Roughening  Surface  of  Concrete  Blocks  to  receive  Fresh  Cement,  at  San  Mateo 

Dam  ^  

98.  San  Mateo  Dam  being  Inspected  by  American  Society  of  Civil  Engineers  in 

July,  1896  °  

99.  Plans  and  Sections  of  San  Mateo  Dam  and  Map  of  Crystal  Springs  Reservoir 

100.  The  Newell  Curve    

101.  Excavation  of  Trench  for  Pacoima  Subterranean  Dam               \  207 

102.  View  of  Flood  passing  over  Pacoima  Subterranean  Dam  \  \  \  209 

103.  Plan  and  Profile  of  Pacoima  Dam  ^  ^  * 

104.  Measuring-box   «••>.. 


xvi  LIST  OF  ILLUSTRATIONS. 

FiauuE  vhQv: 
lOo.  Cross-sections  of  Agna  Fria  Diverting-dam  and  Storage-reservoir  Dam,  Arizona.  218 
100.  Foundations  of  West  Cliannel  of  Agua  Fria  Diverting-dam  215 

107.  Diverting-dam  of  the  Agua  Fria  .facing  x^ag 6  214 

108.  Submerged  Storage-  and  Diverting-dam,  near  Kingman,  Arizon... . . .   219 

109.  Seligman  Dam,  Arizona   220 

110.  View  of  Upper  Face  of  Seligman  Dam  during  Construction  ,   221 

111.  Section  and  Profile  of  Seligman  Dam     222 

112.  Ash  Fork,  Arizona,  Steel  Dam,  View  of  Steel  Construction  from  Lowei  Side . . .  225 

113.  Ash  Fork,  Steel  Dam,  showing  Frame  ready  to  receive  Plates   225 

114.  Ash  Fork  Reservoir   -26 

115.  Walnut  Canyon  Dam,  Arizona  o   227 

116.  Section  and  Profile  of  Walnut  Canyon  Dam,  Arizona   227 

117.  Lynx  Creek  Dam,  Arizona,  after  Rupture  by  Flood.    View  from  below   228 

118  Lvnx  Creek  Dam,  Arizona.  Section  showing  Facing  Walls,  and  Concrete  Hcart- 

mg  •  '  

119.  Inner  Face  of  Concrete  Dain  at  Portland,  Oregon  ,   231 

120.  Exterior  View  of  Reservoir  Dams  at  Portland,  Oregon   233 

121.  Reservoir  No.  2,  Portland,  Oregon,  showing  Aerating  Fountain  125  feet  high..  235 

122.  Masonry  Dam  under  640-foot  Head,  the  Greatest  Recorded  Water-pressure  on 

Masonry  •  •  

123.  Austin  Dam  and  Power-house,  Texas  =   243 

123a.  Austin  Dam,  during  Flood  of  April  7,  1900,  and  immediately  before  the  Break  245 
123&.  Austin  Dam,  Texas.     View  taken  during  Flood,  a  few  Minutes  after  the 

Break   247 

123c.  View  after  Subsidence  of  Flood  of  April  7,  1900,  showing  Section  of  Masonry 

moved  bodily  Down-stream   247 

124.  Upper  Dam  at  Guanajuato,  Mexico  .facing  page  252 

125.  Lower  Dam,  or  "  Presla  de  la  OUa  "  Guanajuato,  Mexico  frontispiece 

126.  The  Ekruk  Tank,  Bombay,  Plan  and  Details.   276 

127.  Cross-section  of  the  Ashti  Dam,  India   278 

128.  View  of  Cuyamaca  Dam  and  Outlet  Tower   282 

129.  Masonry  Diverting-dam  of  the  San  Diego  Flume  Co.,  California   283 

130.  Plan  and  Elevation  of  Diverting-dam  of  San  Diego  Flume  Co.,  California   286 

131.  Sample  of  High  Trestle  Construction  on  San  Diego  Flume,  California   287 

131a.  Map  showing  Location  of  Merced  Reservoir,  California   290 

132.  View  of  Yosemite  Reservoir,  Merced,  California   291 

133.  Reservoir  of  South  Antelope  Valley  Irrigation  Company   301 

134.  Map  of  Little  Rock  Creek  Irrigation  District   302 

135.  View  of  a  Corner  of  the  Basin  of  Alpine  Reservoir  before  Work  was  Begun. ...  303 

136.  Details  of  Tunnel-outlet  of  the  Alpine  Reservoir   306 

137.  Arkansas  River  Basin.    Twin  Lakes  Reservoir-site  facing  page  307 

138.  Detail's  of  Outlets  for  Twin  Lakes,  Colo   308 

139.  The  "Devil's  Gate,"  Sweetwater  River,  Wyoming   317 

140.  Contour  Map  of  Buttes  Reservoir-site,  Gila  River,  Arizona  facing  page  323 

141*.  Longitudinal  Section  of  Buttes  Dam-site,  Gila  River,  Arizona   323 

142*.  Section  of  Proposed  Rock-fill  Dam  at  the  Buttes,  Gila  River,  Arizona   324 

143'  Section  of  Proposed  Buttes  Dam  through  Spillway,  showing  End  Wall  of  Rock 

Fill   ••324 

144.  Plan  of  Buttes  Dam-site,  showing  Location  selected  for  Rock-fill  Dam  facing  page  325 

145.  Plan  of  Riverside  Dam-site,  Gila  River,  Arizona,  showing  Location  selected  for 

Proposed  Masonry  Dam  •'  ■  325 


LIST  OF  ILLUSTRATIONS. 


xvii 


146.  Contour  Map  of  San  Carlos  Reservoir-site,  Gila  River,  Arizona  facing  page  327 

147.  Longitudinal  Profile  of  San  Carlos  Dam-site,  showing  Elevation  of  Proposed 

Masonry  Dam   326 

148.  Contour  Plan  of  San  Carlos  Dam-site,  showing  Location  selected  for  Proposed 

Masonry  Dam  .facing  page  329 

149.  Maximum  Profile  of  Proposed  San  Carlos  Dam  of  Masonry  ,   327 

149«.  Sau  Carlos  Dam-site,  looking  Down-stream  .facing  page  329 

150.  Section  of  San  Carlos  Dam  through  one  of  the  Outlet  Towers,  illustrating 

Arrangement  of  Control   323 

151.  Details  of  Outlet  Tower  and  Gates.    San  Carlos  Dam,  Gila  River,  Arizona  329 

152.  San  Carlos  Dam,  Arizona,  Section  through  Spillway   329 

152a.  San  Carlos  Dam-site,  looking  Down-stream  , ,  33I 

153.  Boring  Apparatus.   330 

154.  View  of  San  Carlos  Dam-site,  Gila  River,  Arizona  333 

154a.  View  of  Left  Abutment  Wall,  San  Carlos  Dam.site,  showing  Dip  of  Lime- 
stone   gg^ 

155.  View  of  the  Buttes  Dam-site,  looking  Down-stream  335 

155a.  Buttes  Dam-site,  looking  Up-stream  from  Upper  Toe    336 

156.  Buttes  Dam-site,  looking  Up-stream ;  Proposed  Quarries  on  Left  ;  Spillway  on 

Left  Center  of  Field   337 

157.  View  of  Riverside  Dam-site,  Gila  River,  Arizona  „  339 

158.  Plan  of  Tonto  Dam   349 

159.  Sections  of  Dam  and  Canyon  of  Tonto  Reservoir  341 

160.  Map  of  Tonto  Basin  Reservoir,  showing  Elevations  of  Ten  Cross-sections  of  the 

Reservoirs   342 

161.  Tonto  Basin  Dam-site,  Salt  River,  Arizona,  looking  Down-stream   343 

162.  Dam-site  on  Salt  River  below  Mouth  of  Tonto  Creek  345 

163.  Map  of  Gila  and  Salt  River  Valleys,  showing  Existing  and  Proposed  Irrigation 

"^^^^^  facing  page  346 

164.  Map  of  Salt  River  Valley,  showing  Canals  Constructed  and  Proposed  facing  page  347 

165.  Map  of  Site  of  Horseshoe  Reservoir,  on  Verde  River  347 

166.  Map  of  Lower  Portion  of  McDowell  Reservoir   349 

167.  Elephant  Butte  Dam  on  Rio  Grande,  above  El  Paso,  Texas.    Plan  and  Section 

of  Dam-site,  Profile  of  Dam,  and  Plan  of  Outlets  355 

168.  Map  of  Elephant  Butte  Reservoir  on  the  Rio  Grande   356 

169.  Diverting-dam  near  Fort  Selden,  Texas,  in  Process  of  Construction   357 

170.  Wood-stave  Pipes,  laid  under  Bed  of  the  Rio  Grande  ^  360 

171.  Map  of  Rock  Creek  Reservoir,  Canal  Lands,  and  Lands  to  be  Irrigated  364 

172.  Plan  of  Dam-site  and  Reservoir-site,  Rock  Creek,  Nevada   365 

173.  Sketch  of  Longitudinal  Section  of  Lost  Canyon  Natural  Dam  366 

174.  Sketch  of  Cross-section  at  Upper  End  of  Lost  Canyon  Natural  Dam   367 

174rz.  Comparison  of  Dams  of  the  System  of  the  Arrowhead  Reservoir  Company  369 

174&.  View  of  Huston  Flat  Reservoir-site  ^   '^r.^ 

175.  Map  of  Little  Bear  Valley  Reservoir  *  '.'facing  page  372 

176.  Map  of  Sources  of  Water-supply  in  the  Vicinity  of  San  Diego,  California 

facing  page  373 

177.  Cross-section  of  Dam-sites  in  San  Diego  County,  California   373 

178.  Map  of  Watershed  and  the  Lands  to  be  Irrigated  from  Victor  Reservoir  374 

179.  Cross-section  of  Dam-site   gr.^ 

180.  View  of  Victor  Dam-site  looking  Up-stream   377 

181.  Map  of  Victor  Reservoir  "  *  * 


xviii  LIST  OF  ILLUSTRATIONS. 

FIGURE  PAGE 

182.  Map  of  Manacbe  Meadows  Reservoir  380 

183.  Map  of  Manaclie  Meadows  Dam-site   381 


PLATES  IN  APPENDIX. 


CALIFORNIA. 

1.  Eleanor  Lake  Reservoir-site. 

2.  Toulume  Meadows  Reservoir-site. 

3.  Little  Yosemite  Reservoir-site. 

4.  Kennedy's  Lake  and  Meadows  Reser- 

voir-site. 

LAHONTAN  BASIN. 

5.  Donner  Lake  Reservoir-site. 

6.  Hope  Valley  Reservoir-site. 

7.  Independence  Lake  Reservoir-site. 

8.  Webber  Lake  Reservoir-site, 

9.  Long  Valley  Reservoir-site. 

ARKANSAS  RIVER  BASIN. 

10.  Cottonwood  Lake  Reservoir-site. 

11.  Sugar  Loaf  Reservoir-site. 

12.  Monument  Reservoir-site. 


13.  Tennessee  Park  Reservoir-site, 

14.  Clear  Creek  Reservoir-site, 

15.  Hayden  Reservoir-site. 
Leadville  Reservoir-site. 

MONTANA. 

16.  Sun  River  Reservoir  System,  Reser- 

voir No.  1. 

17.  Reservoir  No.  2. 

18.  Reservoir  No.  3. 

19.  Reservoir  No.  4. 

20.  Reservoir  No.  5. 

21.  Reservoir  No.  6. 

22.  Reservoir  No.  7. 

23.  Reservoir  No.  8. 

24.  Reservoir  No.  9. 

25.  Benton  Lake  Reservoir. 


EESEEVOIES  FOE  lEEIGATION,  WATEE-POWEE, 
AND  DOMESTIC  WATEE-STJPPLY. 


CHAPTER  I. 

ROCK-FILL  DAMS. 

The  natural  fertility  of  resoarce  ia  the  American  people  has  led  to 
many  novel  experiments  in  the  construction  of  dams  to  adapt  them  to  the 
materials  most  conveniently  available,  and  this  has  resulted  in  the  develop- 
ment of  numerous  interesting  types.  Among  these  the  most  conspicuous 
are  the  ronk-fill  dams,  which  may  be  said  to  have  originated  forty  to  fifty 
years  ago  in  the  mining  region  of  California,  where  dams  were  built  in  re- 
mote and  almost  inaccessible  locations,  to  which  the  transportation  of  cement 
was  impracticable.  These  were  considered  to  be  of  a  temporary  nature,  where 
■dams  of  permanent  masonry  were  not  warranted,  but  where  a  water-supply 
for  mining  purposes  needed  to  be  impounded.  They  began  with  timber  or 
log  cribs  filled  with  loose  stone.  Their  next  stage  was  an  embankment  of 
loose  stone  a  portion  of  which  was  laid  up  as  a  dry  wall,  with  a  facing  of 
-two  or  more  thicknesses  of  plank  to  secure  water-tightness.  The  latter 
type  has  proven  so  serviceable  that  it  is  still  regarded  as  one  of  the  most 
desirable  classes  of  dam  that  can  be  built,  where  economy  is  of  prime  consid- 
eration. In  the  attempt  to  secure  a  greater  degree  of  durability  other  types 
have  been  developed  as  follows : 

1.  Rock-fill  dams  with  facing  of  asphalt  concrete  laid  on  a  sloping  dry 
wall. 

2.  Rock-fill  dams  with  a  central  core  of  steel  plates,  and  without  hand- 
laid  facing- walls. 

3.  Rock-fill  dams  with  facing  of  Portland-cement  concrete  laid  on  dry 
wall. 

4.  Rock-fill  dams  with  facing  of  masonry,  built  vertically,  backed  with 
earth,  and  covered  on  the  lower  side  with  blocks  of  stone  laid  in  mortar. 


2  RESERVOIRS  FOR  IRRIGATION,   WATER-POWER,  ETC. 

5.  Eock-fi]l  dams  with  facing  of  steel  plates  laid  on  the  sloping  interior 
surface  on  a  dry  hand-laid  wall. 

().  Rock-fill  dams  with  facing  of  earth. 

Existing  examples  of  these  various  types  and  the  irrigation  systems  sup- 
plied by  them  will  be  considered  in  the  following  pages. 

The  Escondido  District  Dam,  California. — Few  of  the  irrigation  districts 
organized  in  California  under  the  well-known  Wright  law  have  been  suc- 


FiG.  1.— Map  of  Escondido  Irrigation  District  and  System  op  Works. 


cessfnl  in  accomplishing  the  purpose  of  their  organization,  and.  many 
disastrous  and  lamentable  failures  have  to  be  recorded  in  the  practical 
operation  of  a  law  which,  at  one  time,  was  looked  npon  as  a  wise  and 
feasible  measure  for  the  general  irrigation  of  the  arid  lands  of  the  States. 
Among  the  very  few  that  succeeded  in  selling  bonds  and  constructing  a 
storage-reservoir  and  distributory  system  is  the  Escondido  district  in  the 
northern  portion  of  San  Diego  County.  The  district  (Fig.  1)  is  in  a  valley 
whose  description  is  implied  by  its  Spanish  name,  Escondido — hidden.  It 
is  surrounded  by  mountains  and  embraces  13,000  acres.  The  storage-dam 
supplying  the  district  is  located  on  the  Von  Segern  branch  of  San  Elijo 


II6RARY 
01^  THE 
tiPllV£RSITYoflLLINOk 


BOCK'FILL  DAMS, 


5 


Creek,  which  passes  through  the  town  of  Escondido.  It  is  about  two  miles 
east  of  the  district  at  its  nearest  point,  and  at  an  elevation  of  1300  feet 
above  sea-level,  or  about  650  feet  above  the  town. 

The  immediate  watershed  tributary  to  the  reservoir  measures  about 
8  square  miles,  which  in  that  region  affords  insufficient  run-off  to  fill  the 
reservoir,  although  adding  materially  to  it  at  times  of  heavy  rainfall. 
Hence  the  main  supply  had  to  be  brought  to  it  from  the  San  Luis  Rey 
Eiver,  the  nearest  stream  to  the  north,  by  a  conduit  which  taps  the  river  at 
an  altitude  of  1600  feet,  in  a  wild,  rocky  canyon,  which  is  almost  inaccessi- 
ble by  reason  of  its  roughness.  The  conduit  has  a  capacity  of  28  second- 
feet,  and  is  5.6  miles  long,  consisting  of  67,287  feet  of  ditch  built  along  the 
rugged  mountain-side  (see  Fig.  2),  14,142  feet  of  flume,  and  806  feet  of 
tunnel.  The  intake  is  made  by  a  tunnel  356  feet  long,  heading  in  the  river 
3  feet  below  low-water  level,  while  at  the  other  end  the  rim  of  the  reservoir- 
basin  is  pierced  by  a  second  tunnel  450  feet  long.  This  tunnel  discharges 
into  a  ravine  leading  down  to  the  dam,  3^  miles  below.  The  intake  tunnel 
is  cut  through  solid  granite,  which  is  excavated  below  grade  at  its  lower 
end  to  form  a  settling-basin,  in  which  sand  accumulates  at  the  rate  of  about 
1000  cubic  feet  daily.  This  is  sluiced  back  into  the  river  by  the  opening  of 
a  side  outlet-gate.  By  this  means  the  water  of  the  conduit  is  kept  com- 
paratively clear  and  but  little  sediment  has  accumulated  in  the  reservoir. 

The  upper  8000  feet  of  the  conduit  consists  of  a  flume  (Fig.  3),  sup- 
ported on  posts  on  the  sides  of  a  rugged  canyon,  which  in  places  presents  a 
vertical  face  of  considerable  height.  The  lumber  of  this  flume  was  hauled 
by  a  roundabout  road  to  a  bluff  on  the  opposite  side  and  600  feet  above  the 
river-bed,  whence  it  was  transported  by  a  wire  cable  with  a  span  of  1500 
feet  by  means  of  a  trolley  manipulated  by  hand  windlass  and  rope.  At 
other  points  the  lumber  was  hoisted  to  the  line  by  horse-power,  by  means 
of  a  car  and  portable  track  several  hundred  feet  in  height.  The  flumes 
are  mainly  4  feet  wide  by  3  feet  deep,  and  the  ditch  is  excavated  with  a 
bottom  width  of  5  feet  and  side  slopes  of  1  on  1,  the  minimum  excavation 
on  the  lower  side  being  about  3  feet.  The  formation  throughout  that 
region  is  granitic,  partially  decomposed,  the  disintegration  of  the  rock 
forming  a  few  feet  of  soil,  from  which  protrude  large  bowlders  of  very  hard 
granite  embedded  in  softer  rock  in  situ. 

The  total  cost  of  the  conduit  was  $116,328.60,  or  $1.29  per  foot  for 
construction  and  engineering,  and  12  cents  per  foot  for  right  of  way,  com- 
missions, etc.  The  conduit  is  capable  of  fllling  the  reservoir  to  its  present 
capacity  in  a  little  over  sixty  days  when  running  to  its  full  capacity. 
Should  the  dam  be  completed  to  the  height  of  110  feet  as  it  has  been  pro- 
jected, the  conduit  would  require  to  run  fall  for  rather  more  than  six 
months  to  fill  the  enlarged  reservoir. 

^    In  seasons  when  the  precipitation  exceeds  20  inches  the  run-off  from  the 


6 


BESEEVOIRS  FOR  lURIOATION,   WATKR-POWJm,  KTG. 


immediate  watershed  above  the  dam  is  alone  expected  to  fill  the  reservoir 
as  at  present  constructed.  For  the  preservation  of  the  main  conduit,  of 
which  nearly  20^  is  wooden  flume  which  should  be  kept  wet  for  proper 
maintenance,  it  would  be  desirable  to  maintain  a  flow  of  water  through  it 
the  entire  season.    For  this  purpose  the  construction  of  an  auxiliary  reser- 


YiG.  3. — Feeder  Conduit  of  Escondido  Irrigation  District. 

voir  at  the  head  of  the  conduit  is  regarded  as  one  of  the  most  desirable  of 
the  projected  improvements  to  the  system.  A  very  capacious  reservoir-site 
exists  at  Warner's  Ranch,  15  miles  above  the  head  of  the  canal,  where  the 
drainage  of  210  square  miles  of  watershed  may  be  impounded.  A  much 
greater  volume  of  water  can  here  be  stored  than  would  be  needed  by  the 
district.  In  fact  the  capacity  of  a  reservoir  with  a  dam  100  feet  high  at 
this  point  would  be  193,200  acre-feet,  covering  5535  acres,  which  is  far 
beyond  the  probable  yield  of  the  watershed  in  years  of  maximum  rainfalL 


BOGK'FILL  DAMS.  7 

A  cross-section  of  the  dam-site  is  shown  in  Fig.  4,  where  the  width  of  the 
site  at  100  feet  is  seen  to  be  but  590  feet.  A  more  modest  dam  of  earth, 
36  feet  high,  to  hold  30  feet  depth  of  water  and  to  impound  6400  acre-feet 
in  a  reservoir  covering  740  acres,  wonld  serve  all  the  requirements  of  the 


Fig.  4.— Escondido  Irrigation  Dam,  looking  north,  showing  Spillway. 

district  and  at  moderate  cost,  provided  the  land  is  obtained  at  reasonable 
rates. 

The  Escondido  dam  is  of  the  ordinary  type  of  rock-fill,  with  facing  of 
redwood  plank.  In  this  respect  it  resembles  the  mining  dams  of  northern 
California,  although  the  use  of  redwood  has  given  the  facing  a  longer  life 
than  the  more  perishable  pine  used  in  the  North.  This  structure  appears 
to  have  been  built  with  unusual  care,  and  though  ragged  and  unfinished  in 
appearance,  it  is  of  ample  dimensions  for  the  pressures  it  withstands  and  is 


8  liESEliVOIUS  FOR  IRRIOATION,   WATER-POWER,  ETC. 

reasonably  water-tight.  It  is  70  feet  high,  380  feet  long  on  top,  100  feet 
on  bottom,  with  a  base  of  140  feet,  and  a  thickness  at  the  crest  of  10  feet. 
A  spillway  has  been  excavated  at  the  north  end  on  the  right  bank  of  the 
reservoir,  in  solid  rock,  25  feet  wide,  its  bottom  being  at  the  71-foot 
contour,  or  5  feet  below  the  crest  of  the  dam.  This  is  left  open  and 
unobstracted,  although  it  has  been  customary  near  the  end  of  the  rainy 
season  to  build  a  barrier  of  sand-bags  across  it  in  order  to  impound  a  greater 
depth  of  water,  after  the  danger  of  floods  is  presumed  to  be  over. 

The  slopes  of  the  dam  are  i  to  1  on  the  water-face,  and  on  the  back 
1  to  1  for  half  the  height,  flattening  to  1^  to  1  from  mid-height  to  base. 
The  cubical  contents  are  37,159  cubic  yards,  of  which  6000  yards  were 
hand-laid  in  courses  of  dry  rubble  on  the  face,  the  thickness  of  the  wall 
Ibeing  15  feet  at  bottom,  and  5  feet  at  top.  The  remainder  consists  of 
loose,  angular  blocks  of  granite,  of  all  sizes  up  to  4  tons  weight  (Fig.  5), 
which  were  loosely  dumped  from  cars  and  placed  to  some  extent  with 
derricks.  No  small  quarry-spawls  or  earth  were  used,  and  the  result  is  a 
clean  rock-fill,  which  has  not  settled  more  than  three  inches  since  its  final 
completion.  No  large  ledges  affording  well-defined  quarries  of  any  con- 
siderable extent  were  uncovered  in  the  course  of  construction,  but  all  the 
material  was  taken  from  scattered  bowlders  and  rock-masses  protruding  on 
either  side  of  the  canyon  above  and  below  the  dam  for  a  distance  of  800 
feet.  Temporary  tramways  were  built  at  different  levels  on  either  side,  as 
the  dam  rose  in  height,  so  arranged  as  to  permit  the  cars  to  run  to  the  dam 
by  gravity,  the  empty  cars  being  hauled  back  by  horses.  These  tracks  were 
carried  across  the  dam  on  elevated  trestles,  the  posts  of  which  remain  buried 
in  the  embankment.  This  arrangement  involved  the  pushing  of  the  cars 
across  the  trestle  by  hand,  which  was  a  slow  and  expensive  process.  The 
entire  method  of  work  was  costly  and  inconvenient  compared  with  the 
modern  systems  of  cableway  transportation  of  such  materials. 

In  stripping  the  foundations  bed-rock  was  found  about  4  feet  below  the 
bed  of  the  creek,  nearly  level  across  the  canyon  from  side  to  side.  The  top 
soil  was  removed  over  the  entire  base  of  the  dam  and  the  filling  of  rock 
placed  directly  upon  the  granite  foundation.  The  bed-rock  was  of  the 
formation  described  as  prevailing  along  the  main  conduit,  which  is  a 
common  characteristic  of  southern  California,  and  consists  of  disintegrated 
granite  holding  hard  bowlders  indiscriminately  through  it.  The  formation 
is  not  impervious  to  water,  and  for  that  reason  is  not  considered  a  desirable 
or  satisfactory  foundation  for  a  heavy  masonry  dam  because  of  the  resultant 
upward  pressure  on  the  base  due  to  that  condition,  but  for  a  rock-fill  struc- 
ture of  this  class  it  is  unobjectionable.  Into  this  bed-rock  a  trench  was 
excavated  at  the  upper  toe  of  the  dam,  from  3  to  12  feet  deep,  which  was 
refilled  with  rubble  masonry  5  feet  thick,  laid  in  Portland -cement  mortar. 
Into  this  masonry  was  embedded  the  plank  facing,  which  was  thus 


m  THE 


BOCK-FILL  DAMS.  11 

connected  all  around  the  toe  with  the  canyon  walls  and  bed.  The  dry  wall 
forming  the  upper  face  of  the  dam  was  so  laid  as  to  embed  in  its  surface  a 
series  of  redwood  timbers,  6"  X  6"  in  size,  placed  in  vertical  parallel  lines, 
5  feet  4  inches  apart  between  centers.  These  timbers  projected  2  inches 
beyond  the  face  of  the  wall,  and  the  planks  were  spiked  to  them.  As  each 
row  of  plank  was  put  in  position,  beginning  at  the  bottom,  concrete  was 
rammed  into  the  2-inch  space  between  the  plank  and  the  face  of  the  wall, 
giving  a  fall  bearing  for  the  plank  throughout.  This  provision  was 
certainly  a  wise  one,  and  so  far  as  the  writer  is  informed  was  never  employed 
before  in  the  dams  of  this  class  previously  constructed.  On  the  lower  third 
of  the  dam  the  facing  plank  are  3  inches  thick,  on  the  middle  third 
2  inches,  and  on  the  upper  third  1^  inches,  all  being  doubled  throughout 
Joints  were  broken  as  far  as  possible,  both  at  the  vertical  and  the  horizontal 
seams,  by  the  second  layer,  and  they  were  calked  with  oakum  and  smeared 
with  hot  asphaltum. 

Springs  of  water  were  developed  in  the  excavation  of  the  foundation  to 
the  extent  of  30,000  to  40,000  gallons  per  day,  constant  flow.  These  were 
led  out  by  pipes  to  the  outer  toe.  The  leakage  through  the  dam  when 
flUed  to  the  47-foot  level  was  found  to  be  130,000  gallons  daily,  exclusive 
of  the  springs.  This  increased  to  450,000  gallons  daily  when  the  reservoir 
filled  to  the  top.  It  is  not  known  whether  this  leakage  comes  through  the 
joints  of  the  facing  or  percolates  through  the  disintegrated  granite  beneath 
the  dam.  Whatever  may  be  its  origin,  it  is  entirely  harmless  as  far  as  can 
be  observed,  and  is  not  a  source  of  anxiety.  In  the  winter  months  when 
irrigation  is  not  required  this  leakage-water  is  used^  for  domestic  service, 
and  the  whole  of  it  is  at  all  times  picked  up  by  the  diverting-dam  and 
carried  into  the  distributing  system.  Hence  it  occasions  no  direct  loss  of 
water.  While  this  amount  of  leakage  would  be  dangerous  to  an  earth  dam, 
and  e^en  in  a  masonry  structure  would  indicate  the  existence  of  an  upward 
pressure  that  might  endanger  its  stability  if  the  section  were  too  light,  yet 
in  a  work  of  this  nature  the  drainage  through  the  open,  loose  rock  is  so 
perfect  that  the  gravity  of  the  mass  is  not  lessened  or  disturbed  by  it,  and 
no  serious  consequence  can  be  anticipated. 

The  facing-planks  have  been  carried  up  3  feet  higher  than  the  top  of 
the  rock-fill  as  a  wave  protection,  so  that  the  extreme  crest  is  9  feet  above 
the  floor  of  the  spillway  as  shown  by  the  section  illustrated  in  Fig.  6. 

The  outlet  was  originally  designed  to  be  controlled  by  means  of  a  tower, 
the  foundations  of  which  were  laid  at  the  upper  toe  of  the  dam  near  the 
south  end,  but  the  plan  was  changed  and  a  grating  placed  over  the  base  of 
the  unfinished  tower  a  few  feet  above  the  gate  covering  the  outlet.  The 
gate  is  of  cast  iron  with  brass  facings,  set  in  a  frame,  also  faced  with  brass, 
and  bolted  to  the  cast-iron  outlet.  It  is  set  at  the  incline  of  the  upper 
slope  and  is  controlled  by  a  long  rod  resting  in  guides  at  frequent  intervals, 


BOCK-FILL  DAMS. 


13 


fastened  to  the  wooden  facing,  and  leading  to  a  worm-gear  placed  at  a  con- 
venient height  above  the  top  of  the  dam  (Fig.  7).  The  outlet-pipe  is  24 
inches  in  diameter,  consisting  of  a  cast-iron  elbow  connecting  with  vitrified 


Fig.  7.— Details  of  Gate  of  Escondido  Dam. 


sewer-pipe  of  ordinary  weight,  laid  in  a  trench  cut  in  the  bed-rock  and 
embedded  in  concrete,  which  covers  it  fully  12  inches  in  depth. 

The  total  cost  of  the  dam  under  the  contract  was  $86,946.21,  or  $27.82 
per  acre-foot  of  reservoir  capacity  below  the  spillway  level.    The  land  for 


14  EKSERV01R8  FOR  IRRIGATION,   WATER-POWER,  ETC. 

the  site  cost  in  addition  $23,112.88,  including  clearing.  The  total  cost 
was  therefore  1110,059.09,  or  138.41  per  acre-foot  of  capacity.  The 
prices  paid  were  unusually  high  for  such  work,  and  were  the  following  per 
cubic  yard:  earth  excavation,  30  cents;  rock  excavation,  $1.10;  rock-fill, 
$1.50;  dry  stone  masonry,  $3.75;  rubble  masonry  in  cement  mortar,  $8; 
concrete,  $14;  lumber,  $50  per  thousand  feet  board  measure. 

The  detail  of  this  work  is  given  with  special  fullness,  as  it  is  the  first 
rock-fill  dam  to  be  constructed  in  California  for  irrigation  storage,  and  is 


IjiKIGATION  DiSTKICT. 

of  a  type  which  is  likely  to  be  employed  quite  commonly  in  the  future  in 
localities  better  adapted  for  its  use  than  in  this  particular  case,  where  stone 
was  comparatively  scarce  in  the  immediate  vicinity  of  the  dam. 

The  Distributing  System.— Owing  to  the  rolling  character  of  the  topog- 
raphy over  a  considerable  portion  of  the  Escondido  District  the  system  of  dis- 
tribution of  water  necessarily  consisted  largely  of  pressure-pipes,  alternating 
with  ditches  and  flumes.  Water  is  released  from  the  dam  into  the  rocky  bed 
of  the  canyon  in  which  it  flows  for  half  a  mile  to  a  small  masonry  weir,  built 
on  solid  bed-rock,  illustrated  in  Fig.  8.  The  main  conduit  heads  here  with 
a  flume,  having  a  capacity  of  20  second-feet.    The  laterals  leading  from 


RGCK-FTLL  DAMS. 


15 


this  conduit  have  capacities  of  from  1  to  10  second-feet.  When  completed 
in  1895  the  distributing  system  consisted  of  14.5  miles  of  riveted  steel  pipes, 
3  to  20  inches  in  diameter,  2  miles  of  flumes,  1.5  miles  of  vitrified  clay  and 
cement  pipes,  and  13.5  miles  of  open  ditches  in  earth — a  total  of  31.5  miles. 
During  1897,  '98,  and  '99  about  11  miles  of  the  open  ditches  in  earth  have 
been  lined  with  cement  to  prevent  loss  of  water  by  leakage;  4^  miles  of 
vitrified  pipe  from  5  to  14  inches  in  diameter  have  been  laid,  also  1.15  miles 
of  4-  and  6-inch  cement  pipe,  0.87  mile  of  2-,  3-,  and  4-inch  iron  pipes, 
and  0.16  mile  of  8-inch  wood  pipe.  In  addition  to  this  are  15  miles  of 
2-  and  4-inch  pipes  that  formed  the  domestic-supply  system  of  the  town 
of  Escondido,  which  is  a  part  of  the  irrigation  district,  and  is  provided  with 
domestic  water  by  the  district  in  the  same  proportion  as  a  similar  area  of 
farming  lands.  This  town-distributing  system  was  in  private  ownership 
prior  to  the  organization  of  the  district,  and  was  supplied  by  wells  and 
pumps.  It  was  purchased  by  the  district  for  $9000  in  bonds,  and  there 
was  included  in  the  purchase  a  lined  and  covered  reservoir  of  800,000 
gallons  capacity,  a  Worthington  steam-pump  of  500,000  gallons  daily 
capacity,  three  20-foot  brick-lined  wells,  20  feet  deep,  and  twenty  2-inch 
driven  wells,  all  connected  by  suction-pipes  to  the  main  pump.  This 
auxiliary  pumping  supply,  though  small  in  amount,  is  very  convenient  to 
draw  upon  for  domestic  service  in  the  late  summer  and  fall  when  the  water 
in  the  reservoir  becomes  foul  and  unfit  for  domestic  use.  The  entire  first 
cost  of  the  distributing  system  was  $85,727.80. 

The  works  of  the  district  summarize  in  cost  as  follows: 

Main  feeder  conduit   $116,328.60 

Dam  and  reservoir   110,059.09 

■     Distribution  system     85,727.80 

Total   $312,115.49 

The  first  issue  of  bonds  by  the  district,  out  of  the  total  amount  of 
$350,000  authorized,  was  $344,500,  which  realized  in  cash  or  its  equivalent 
$313,750,  all  of  which  was  expended  on  first  construction.  The  proceeds 
of  the  remaining  $5500  of  bonds,  together  with  $2500  additional  raised  by 
taxation,  were  expended  in  the  early  part  of  1897  in  lining  the  main  dis- 
tributing ditches  with  cement  plaster. 

The  irrigators  using  water  in  1897  were  225  in  number,  cultivating 
1575  acres,  chiefly  planted  to  citrus  fruits.  In  addition  to  these  the  taps 
on  the  distributing  system  in  the  town  numbered  204. 

The  annual  expense  of  operating  the  system,  is  about  $4000,  while  the 
interest  on  the  bonds  at  6^  amounts  to  $21,000  per  annum.  The  bonds 
run  for  twenty  years,  but  their  retirement  begins  on  the  tenth  year  from 
their  issuance,  and  are  payable  thereafter  at  the  rate  of  one-tenth  each  year. 
The  total  annual  expense  for  salaries  and  interest  divided  by  the  number  of 


ROCK-FILL  DAMjS. 


17 


acre-feet  of  reservoir  capacity  brings  the  annual  cost  per  acre-foot  of  avail- 
able water  to  about  $8.  Taking  into  account,  however,  the  losses  by 
evaporation  in  the  reservoir  and  leakage  from  the  ditches  and  flumes  in 
transit,  the  cost  of  water  actually  available  for  use  on  the  lands  is  not  far 
from  $12.50  per  acre-foot,  or  nearly  4  cents  per  1000  gallons.  The  average 
requirement  for  adequate  irrigation  is  estimated  at  about  12  inches  in  depth, 


Fig.  10.— Construction  op  Facung  ov  Ej-condido  Dam 


or  1  acre-foot  per  acre.  At  this  rate  the  district  when  fully  irrigated  would 
need  13,000  acre-feet,  or  nearly  four  times  the  present  capacity  of  the 
reservoir.  The  total  annual  expenses  divided  by  the  total  area  of  the 
district  gives  an  average  of  about  $1. 80  per  acre.  The  assessed  valuation 
of  the  district  iu  1897  was  1677,500,  and  the  tax-rate  assessed  by  the  direct- 
ors for  irrigation  expenses  was  $3.69  per  $100.  As  the  best  land  was 
assessed  at  $40  per  acre,  it  was  shown  on  that  basis  that  the  average  cost  to 


IS  RESERVOIUS  FOR  IRRIGATION,   WATKR-POWER,  ETC. 

the  owner  was  but  11.48  a,ii  acre,  which  is  a  low  rate,  provided  the  payment 
of  the  tax  would  insure  him  a  sufficient  supply  for  the  irrigation  of  his 
land;  but  as  the  provision  thus  far  made  for  the  district  in  water-supply  is 
less  than  one-fourth  of  what  will  ultimately  be  required  to  irrigate  the 
whole  district,  and  as  the  water  available  is  apportioned  to  the  irrigator  pro 
rata  to  the  amount  of  tax  he  pays,  his  annual  rate  must  necessarily  be 
higher  than  the  amount  stated  if  he  receives  the  water  he  actually  requires. 

The  apportionment  is  made  in  regular  runs,  once  each  month,  beginning 
at  the  head  of  the  system,  and  in  order  to  accomplish  the  satisfactory  irri- 
gation of  their  tracts  the  orchardists  are  obliged  to  buy  what  water  they 
lack  of  full  supply  from  such  of  the  neighboring  taxpayers  as  do  not  yet 
use  the  water  to  which  they  are  legally  entitled.  This  assigned  water  is 
sold  at  about  10  cents  per  miner's  inch  for  24  hours'  run,  which  is  about 
one-third  cost.  During  1897  the  water  thus  transferred  was  about  9488 
inches  for  24  hours.  A  toll  of  1  cent  per  24-hour  inch,  or  25  cents  as  a 
minimum,  is  charged  as  a  gate-tax  for  zanjero's*  fees  for  turning  water  on 
and  off,  which  brings  in  a  revenue  of  about  $80  per  month  during  the 
irrigating  season,  and  160  per  month  during  the  rest  of  the  year.  This  toll 
was  increased  in  1899  to  40  cents,  which  covers  all  costs  of  operating. 

The  selling-price  of  water  has  steadily  advanced  during  the  late  years  of 
drought.  In  1897  it  was  sold  at  5  to  20  cents  per  miner's  inch  for  24  hours 
(12,960  gallons).  In  1898  the  rates  were  increased  to  25  to  35  cents  per 
inch,  and  in  1899  they  were  50  to  60  cents  per  inch.  The  catchment  of 
the  reservoir  has  been  approximately  as  follows: 

1895,  48    feet  depth  =    880  acre-feet 

1896,  60     "      "      =  1925  " 

1897,  74     "      "         3700  " 

1898,  59.5  "      "      =  1000  " 

1899,  47     "      "      =    830  " 


'Total   8335  acre-feet,  or  an  average  of  1667  per  annum. 

A  large  number  of  orchards  had  been  started  and  were  being  irrigated 
by  water  pumped  from  wells  by  windmills  and  gasoline  engines  before  the 
completion  of  the  works  of  the  district.  The  cost  of  pumping  by  the 
various  mxcthods  employed  ranged  from  3  to  8  cents  per  1000  gallons  ($10 
to  $26  per  acre-foot),  and  this  high  cost,  coupled  with  a  very  moderate  and 
inadequate  supply,  caused  many  of  the  landowners  whose  property  was  not 
incorporated  in  the  district  to  seek  admission  on  equal  terms  with  those 
inside.  Several  hundred  acres  were  thus  taken  in  after  the  works  had  been 
completed  to  the  present  stage  upon  payment  of  all  back  charges  pro  rata. 


*  From  the  Spanish,  meaning  ditch-tender. 


ROCK-FILL  DAMS. 


19 


The  residents  of  the  district  realize  that  their  works  are  ia  an  incomplete 
stage,  and  that  to  secure  an  adequate  supply  it  is  necessary  to  carry  the 
gtorage-dam  40  feet  higher,  giving  it  a  capacity  of  11,355  acre-feet.  This 
can  readily  be  done  at  a  cost  not  to  exceed  1110,000.  The  land  purchased 
for  the  reservoir  covers  the  enlarged  area  proposed,  and  it  is  only  necessary 
to  continue  the  embankment  higher,  adding  the  necessary  width  of  base  to 
give  the  same  safe  slopes  which  the  present  embankment  possesses,  and 
extending  the  wood-facing.  With  this  improvement,  and  the  addition  of 
the  smaller  regulating  reservoir  on  the  river  before  mentioned,  it  is  believed, 
that  the  district  will  have  an  ample  sQpply  for  its  needs  at  a  total  outlay  of 
about  $40  per  acre,  and  an  average  annual  expense  of  12.50  to  13  per  acre. 

During  the  fall  of  1897  the  validity  of  the  bond  issue  was  questioned  by 
a  portion  of  the  landowners,  many  of  whom  ceased  paying  the  tax  levied 
to  meet  the  interest  on  the  bonds.  In  March,  1899,  the  bondholders 
requested  the  trustee,  the  Farmers  and  Merchants'  Bank  of  San  Diego,  to 
take  charge  of  the  system  according  to  the  terms  of  the  trust  deed,  and  as 
provided  by  the  Wright  Act  under  which  the  district  is  organized.  This 
was  done,  and  the  former  superintendent  was  continued  as  manager. 

Lower  Otay  Rock-fill  Steel-core  Dam,  California. — One  of  the  most 
interesting  of  all  the  rock-fill  types  of  dam  yet  constructed  is  located  on 
Otay  Creek,  San  Diego  County,  California,  22  miles  southeast  of  San 
Diego,  10  miles  back  from  the  coast,  and  not  more  than  5  miles  from  the 
Mexican  boundary-line.  It  forms  the  lower  one  of  a  series  of  four 
mammoth  dams  projected  by  the  Southern  California  Mountain  Water 
Company,  to  impound  water  for  the  municipalities  of  San  Diego  and 
Coronado  and  for  the  irrigation  of  an  extensive  area  of  f rostless  mesa  lands 
adapted  to  citrus-fruit  culture,  reaching  from  the  Mexican  border  north- 
ward to  San  Diego,  including  the  peninsula  of  Coronado,  and  for  the 
domestic  supply  of  the  villages  and  towns  within  reach  of  the  distributing 
system  to  be  built  from  the  reservoir.  This  system  of  reservoirs  and 
conduits  is  the  most  comprehensive  one  yet  projected  in  California  for 
irrigation  purposes,  and  when  completed  in  its  entirety  it  must  add  so 
greatly  to  the  productive  area  and  population  of  the  region  in  the  vicinity 
of  the  Bay  of  San  Diego  as  to  bring  that  port  into  the  prominence  in  the 
world's  commerce  which  its  general  excellence  as  a  harbor  has  long  deserved. 
The  Lower  Otay  dam  was  completed  in  August,  1897,  and  the  Morena  and 
Barrett  dams,  the  other  two  of  the  series,  have  been  under  construction 
since  that  time,  although  both  are  still  far  from  completion. 

The  Otay  Creek,  at  the  point  selected  for  the  dam,  cuts  through  the 
great  dike  of  porphyry  which  traverses  San  Diego  County  from  north  to 
south  nearly  parallel  with  the  coast-line.  This  dike  in  places  is  10  miles 
or  more  in  width,  and  at  others  less  than  1  mile,  and  occupies  the  middle 
ground  between  the  granite  formation  lying  east  of  it,  and  the  mesa  forma- 


20  RESERVOIRS  FOR  IRlilOATION,  WATER-POWKR,  ETC. 


tion,  which  is  an  irregular  strip  of  land,  10  to  15  miles  wide,  lying  between 
the  porphyry  dike  and  the  shore  of  the  Pacific.  The  mesa  formation  is 
alluvial  in  origin;  consisting  of  marl,  indurated  sand,  gravel,  cobbles,  and 
all  shades  of  soil  from  clay  to  sandy  loam,  but  is  devoid  of  hard  rock,  while 
the  porphyry  is  an  igneous  rock,  exceedingly  tough,  of  high  specific 
gravity,  without  regular  cleavage,  but  broken  by  numerous  fine  seams  with 
infiltration  of  reddish  clay.  The  highest  protrusions  of  the  dike  form  tlie 
San  Ysidro  and  San  Miguel  mountains,  2500  to  3000  feet  in  altitude.  It 
is  intersected  by  all  the  streams  of  the  county  that  reach  to  the  ocean, 
affording  sites  for  the  Lower  Otay,  the  Upper  Otay,  the  Sweetwater  and 
La  Mesa  dams,  and  others  farther  north  that  are  projected.  The  Escondido 
dam  is  but  a  mile  or  two  east  of  the  dike  in  granite  formation.  The  Otay 
dam  is  within  a  few  hundred  feet  of  the  western  limit  of  this  dike,  and  in 
fact  the  outlet  tunnel  of  the  reservoir  avoids  it  entirely  and  was  excavated 
through  the  soft  brown  marl  of  the  mesa  formation. 

The  site  of  the  Otay  dam  was  an  ideal  one  for  a  masonry  structure, 
because  of  the  satisfactory  character  of  the  bed-rock  foundations,  and  the 
abundance  of  suitable  rock  and  sand  at  the  site,  while  its  convenience  to  a 
port  of  entry  rendered  the  cost  of  cement  very  moderate.  The  usual 
incentive  for  building  rock-fill  dams  in  preference  to  masonry,  due  to  their 
remoteness  and  the  high  cost  of  freighting  cement  to  the  site  was  lacking 
in  this  case,  and  in  fact  the  work  was  originally  planned  as  a  masonry  dam. 
A  foundation  was  laid  for  this  purpose  65  feet  thick  at  the  base^  reaching 
down  to  a  depth  of  31.4  feet  below  zero  contour,  and  carried  up  to  a  height 
of  8.6  feet  above  zero,  with  a  length  on  top  of  85  feet.  A  view  of  the  work 
is  shown  in  Fig.  11. 

"Whether  the  change  in  plan  from  masonry  to  rock-fili  with  steel  core 
has  resulted  in  economy  of  first  cost  is  difficult  to  determine,  as  the  actual 
cost  of  construction  has  not  been  made  public,  or  whether  there  may  be 
grounds  for  regret  that  the  change  was  made  cannot  be  known  until  the 
stability  of  the  structure  is  fully  tested  by  the  lapse  of  time.  The  reservoir 
has  never  filled  above  the  60-foot  contour  since  the  completion  of  the  dam 
up  to  the  fall  of  1900,  and  until  the  reservoir  is  filled  and  remains  full  a 
considerable  period  without  developing  signs  of  weakness  or  extensive 
leakage  the  success  of  the  novel  design  cannot  be  known.  Meantime  the 
engineering  profession  will  entertain  the  liveliest  interest  in  the  develop- 
ment of  this  novel  type  of  dam,  which,  if  successful,  will  certainly  have 
wide  application  to  other  sites  where  the  choice  of  material  has  a  more 
limited  range.  The  credit  for  originating  the  idea  of  making  a  rock-fill 
dam  water-tight  by  inserting  in  its  center  a  web-plate  of  steel,  filling  the 
entire  cross-section  of  the  canyon  from  side  to  side,  and  for  putting  it  in 
application  on  a  large  scale,  belongs  to  the  president  of  the  water  company, 
Mr.  E.  S.  Babcock,  of  Coronado.    When  this  plan  was  decided  upon  a 


ROCK-FILL  DAMS. 


21 


heavy  T  iron  was  anchored  to  the  top  of  the  finished  masonry  foundation 
by  1-inch  bolts,  set  in  the  masonry.  The  vertical  leg  of  the  T  was  punched 
with  f-inch  rivet-holes,  spaced  3  inches  center  to  center,  and  the  bottom 
plates  riveted  to  it.  The  plates  were  5  feet  wide,  and  17.5  feet  long,  and 
the  three  bottom  courses  were  0.33  inch  thick.  From  28  to  50  feet  high 
they  are  ^  inch  thick,  and  above  50  feet  they  are  8  feet  wide,  20  feet  long, 
and  lessening  in  thickness  as  the  top  is  approached.    After  riveting  the 


Fig.  11  — Masonry  Foundation  of  Lower  Otay  Dam. 


plates  together  with  hot  rivets  they  were  chipped  and  calked  on  the  side 
next  to  the  water,  and  coated  with  Alcatraz  asphalt,  F  grade,  applied  hot 
with  brushes.  Over  this  coat  a  layer  of  burlap  was  placed  on  each  side  of 
the  plates,  while  the  asphalt  was  still  hot.  This  adhered  tightly  to  the 
plate  and  served  to  hold  the  soft  asphalt  from  flowing.  A  harder  grade  of 
asphalt  was  subsequently  put  on  over  the  burlap,  and  the  whole  then 
encased  in  a  rubble-masonry  wall  laid  with  Portland-cement  concrete,  2  feefc 
thick,  the  steel  plate  being  in  the  centre.    This  wall  at  base  is  6  feet  thick, 


22 


BESEEVOinS  FOR  IRUIQATION,  WATER-POWm,  ETC. 


tapering  to  2  feet  in  a  lieiglit  of  8  feet.  The  moulds  for  the  concrete,  con- 
sisting of  1-inch  boards  laid  horizontally  and  2  X  G-inch  vertical  posts,  were 
left  in  position  j^ermanently  and  the  rock-fill  built  against  them  on  either 
side.  The  steel  core,  or  web-plate,  was  carried  into  the  side  walls  of  the 
canyon  in  a  trench  excavated  to  the  depth  necessary  to  reach  solid  rock  and 
anchored  with  bolts  leaded  into  the  rock.  The  end  plates  were  not  trimmed 
to  fit  the  irregular  line  of  the  rock  cutting,  but  the  masonry  was  widened 
to  a  maximum  thickness  of  20  feet  at  the  sides,  tapering  from  the  normal 
thickness  of  2  feet  in  a  distance  of  about  20  feet.  Fig.  12  shows  the  trench 
on  the  right  bank  about  at  the  40-foot  contour.  The  function  of  the  wall 
is  to  steady  and  stiffen  the  web-plate  and  protect  it  from  injury  from  the 
loose  rock  piled  against  it,  and  as  the  wooden  moulds  were  not  removed  the 
embankment  is  free  to  settle  without  injuring  the  concrete  or  the  plates. 

The  expansion  of  the  plates  after  they  were  riveted  together,  and  the 
obtuse  angle  up-stream  on  which  they  were  first  started,  which  gradually 
was  obliterated  by  an  approach  to  a  straight  line  toward  the  top  of  the 
dam,  gave  them  a  very  irregular  alignment,  as  w^ill  be  seen  in  Fig.  13,  which 
is  a  view  looking  along  the  top  of  the  dam  toward  the  left  bank  just  before 
its  completion. 

The  dam  is  a  loose,  rock-fill  embankment,  lying  as  it  was  dumped, 
without  any  portion  of  it,  except  the  2-foot  core-wall,  being  laid  by  hand. 
In  this  respect  it  differs  from  its  predecessors  of  the  same  type,  which  have 
been  built  with  a  considerable  proportion  of  their  slopes  on  the  water-side 
laid  up  as  a  dry  wall.  It  was  designed  to  be  20  feet  wide  at  top,  with  side 
slopes  of  1^  on  1  on  each  side.  When  work  was  suspended  the  up-stream 
slope,  composed  of  the  finer  grades  of  materials  coming  from  the  quarry, 
had  assumed  about  the  slope  stated,  but  the  lower  slope  was  steeper  and 
stands  about  1  to  1,  while  the  top  width  is  from  9  to  12  feet.  When 
visited  by  the  writer  in  September,  1899,  the  material  excavated  from  the 
spillway  cut  was  being  dumped  on  the  upper  slope  and  the  top  width 
increased.  The  spillway  is  located  some  few  hundred  feet  from  the  east 
end  of  the  dam,  and  will  consist  of  a  channel  30  feet  wide,  300  feet  long, 
with  a  maximum  depth  of  30  feet,  cut  in  the  rock  to  a  depth  of  10  feet 
below  the  crest  of  the  dam.  The  depth  of  water  will  be  controlled  by 
flash-boards  resting  at  an  angle  of  30°,  between  channel-iron  frames  placed 
5  feet  apart.  A  wagon-bridge  will  be  built  over  the  top  of  these  frames, 
from  which  full  control  of  the  flash-boards  will  be  had.  The  discharge  of 
the  spillway  will  reach  the  creek  channel  several  hundred  feet  below  the 
toe  of  the  embankment. 

The  entire  volume  of  stone  used  in  the  work,  approximately  180,000 
cubic  yards,  was  quarried  immediately  below  the  dam  on  the  right  bank, 
and  was  transported  from  the  quarry  by  means  of  a  Lidgerwood  cableway, 
the  cable  having  a  diameter  of  2^  inches,  and  a  span  of  948  feet  between 


ROCK-FILL  DAMS. 


25 


towers,  crossing  the  canyon  diagonally,  at  an  angle  of  about  60°  with  the 
axis  of  the  dam.  The  head  tower  was  130  feet  high,  the  tail  tower  down- 
stream 60  feet  high,  the  tops  being  practically  level,  and  a  direct  line 
between  them  crossed  the  axis  of  the  dam  260  feet  above  the  bed  of  the 
stream.  The  cableway  had  a  guaranteed  capacity  of  10  tons,  center  load, 
under  which  its  deflection  was  88  feet,  or  42  feet  higher  than  the  top  of  the 


Fig.  13.— Crest  of  Lower  Otay  Dam,  showing  Wku-plate  op  Steel  embedded 
IN  Concrete.    Dam  nearing  Completion. 

dam.  Up  to  the  height  of  75  feet  the  rock  dumped  under  the  line  of  the 
cable  was  distributed  by  means  of  derricks,  but  subsequently  a  secondary 
cableway  was  'erected  parallel  with  the  line  of  the  dam,  underneath  the 
mam  cable.  This  was  anchored  at  each  end  to  heavily  ballasted  cars  rest- 
ing on  tracks,  which  permitted  the  cable  to  be  shifted  30  feet,  or  15  feet 
either  side  of  the  center  of  the  dam.  The  loaded  skips  from  the  quarry 
brought  to  the  dam  by  the  overhead  cable  were  picked  up  by  the  secondary 
cable  and  carried  to  any  point  desired  along  the  line  of  the  dam.  Tools, 
materials,  derricks,  35-H.P.  hoisting-engines,  and  all  other  articles  required 


BESERV0IU8  FOB  IRIIIOATION,  WATER  POWER,  ETC. 


ROCK-FILL  DAMS. 


27 


to  be  moved  from  one  position  to  another  were  hauled  rapidly  and  safely  by 
means  of  these  cableways,  and  not  infrequently  the  employees  preferred  the 
aerial  journey  across  the  canyon  by  the  cableway  to  the  more  laborious 
climb  over  the  trails.  Fig.  15  illustrates  the  general  plan  of  the  dam,  with 
a  cross-section  of  the  site  and  details  of  the  outlet  tunnel. 

Quarry. — All  or  the  greater  portion  of  the  rock  had  been  loosened  in 
the  quarry  by  very  heavy  blasts,  the  first  of  which  was  made  by  driving  a 
tunnel  50  feet  into  the  face  of  the  cliff  with  lateral  drifts,  18  and  28  feet 
long  respectively.  In  the  shorter  drift,  4000  pounds  of  Judson  powder 
(containing  5^  nitro-glycerine)  under  a  vertical  depth  of  70  feet,  and  in  the 
larger,  8000  pounds  under  a  depth  of  85  feet,  were  exploded  simultaneously, 
V7hicli  resulted  in  loosening  and  throwing  out  about  50,000  to  75,000  cubic 
yards.  A  view  of  this  blast  taken  at  the  moment  of  explosion  is  shown  in 
Fig.  16.  The  second  large  blast  was  prepared  by  sinking  a  shaft  115  feet 
deep,  85  feet  back  from  the  nearly  vertical  face  left  by  the  first  blast.  At 
a  depth  of  50  feet  two  drifts  were  run  laterally  a  distance  of  25  feet  each, 
and  at  the  bottom  of  the  shaft  two  more  drifts,  30  and  35  feet  long  respec-  ^ 
tively,  were  extended  into  the  rock  toward  the  face  and  in  the  opposite 
direction,  and  the  four  holes  thus  prepared  were  loaded  with  30,000  pounds 
of  powder,  of  which  the  greater  portion  was  located  in  the  bottom  drifts. 
This  blast  did  greater  execution  than  the  first,  and  supplied  sufficient  rock 
to  complete  the  dam.  Minor  blasting  of  the  ordinary  class  was  necessary 
throughout  the  work  to  break  up  the  larger  masses  to  sizes  that  could  be 
handled  by  the  cableway.  The  quarry  being  near  the  lower  toe  of  the  dam, 
the  first  large  blast  filled  in  the  toe  with  large  bowlders,  some  of  which 
weighed  upwards  of  50  tons,  and  a  subsequent  freshet,  pouring  over  and 
through  these  rocks,  scoured  out  the  sand  beneath  them  so  as  to  settle  them 
well  to  bed-rock,  which  was  a  fortunate  occurrence. 

The  watershed  of  Otay  Creek  above  the  reservoir  is  about  100  square 
miles  in  area,  but  as  its  average  altitude  is  not  over  1600  feet  the  precipita- 
tion is  light  and  the  run-off  insufficient  to  fill  the  reservoir  except  in  occa- 
sional years.  In  dry  seasons  there  is  no  flow  whatever.  The  catchment  in 
four  years  prior  to  September,  1899,  has  not  exceeded  5000  acre-feet.  To 
make  up  for  this  shortage  in  supply  and  to  fill  the  reservoir  regularly  the 
company  is  planning  to  divert  water  from  Cottonwood  Creek,  a  stream 
adjoining  on  the  south  which  drains  an  extensive  region  of  the  highest 
mountains  of  the  main  range.  This  stream  enters  Mexican  territory  and 
returns  again,  emptying  into  the  sea  near  the  boundary-line,  where  it  is 
known  as  the  Tia  Juana  River.  The  conduit  for  diverting  its  flow  will 
start  at  the  second  reservoir  of  the  system,  known  as  the  "  Barrett  dam," 
at  an  elevation  of  80  feet  above  the  stream-bed,  or  about  1650  feet  above 
sea-level,  and  be  supported  along  the  southerly  slopes  of  Lyon's  Peak  to 
Dulzura  Pass,  where  the  divide  will  be  crossed  by  a  long  tunnel,  from  which 


UNlVERSiryoflLLINOIl 


ROCK-FILL  DAMS. 


31 


the  water  will  drop  into  the  east  fork  of  Otay  Creek  and  thence  to  Otay 
reservoir.  The  conduit  will  be  a  trifle  over  8  miles  in  length,  and  consist 
of  a  succession  of  cement-lined  tunnels  in  granite.  To  regulate  the  flow  of 
the  stream  and  store  additional  water  the  company  have  under  construction 
two  dams  of  mammoth  size — the  Barrett  and  Morena,  both  of  which  have 
been  projected  as  rock-fill  dams. 

Outlet  Tumiel. — There  are  no  pipes  or  outlets  through  or  under  the 
dam  proper,  and  the  only  outlet  provided  is  a  circular  tunnel  through  a 
narrow  part  of  the  enclosing  ridge  1000  feet  west  of  the  dam.  This  tunnel 
is  1150  feet  long,  the  bottom  of  which  is  at  the  48-foot  contour.  Below 
the  tunnel-level,  therefore,  as  will  be  seen  by  reference  to  the  table  of  reser- 
voir capacities  in  the  Appendix,  there  remains  a  volume  of  water  of  approxi- 
mately 2000  acre-feet  (652,400,000  gallons),  covering  nearly  160  acres  of 
surface  which  can  never  be  drawn  off.  The  material  encountered  in  this 
tunnel  was  a  brown  hard-pan,  resembling  marl,  and  cemented  gravel,  both 
bone-dry.  The  western  limit  of  the  porphyry  dike  is  between  the  tunnel 
and  the  dam.  For  500  feet  from  the  inner  heading  the  tunnel  was  lined 
with  concrete  to  a  clear  circular  diameter  of  5  feet,  the  lining  being  12  to 
18  inches  thick  and  plastered  with  cement  mortar.  At  the  end  of  this 
section  a  shaft,  104  feet  in  depth,  reaches  to  the  surface.  Below  this  shaft 
a  48-inch  riveted  steel  pipe  is  laid  to  the  outside,  and  the  entire  annular 
space  between  the  pipe  and  the  walls  of  the  tunnel  is  filled  with  concrete, 
with  a  minimum  thickness  of  12  inches,.  This  pipe  was  put  together  in 
sections  of  38  inches  in  length,  stovepipe  fashion,  the  insertion  at  each 
joint  being  2  to  3  inches.  The  joints  were  driven  as  closely  as  possible,  but 
owing  to  the  sag  of  the  pipe  and  the  absence  of  careful  ramming  of  the 
concrete  at  the  bottom  of  the  joint  it  was  found  on  completion  that  there 
were  cavities  which  rendered  it  impossible  to  calk  the  joints  from  the  inside 
and  make  them  water-tight.  As  it  was  desirable  to  utilize  the  full  depth 
of  the  reservoir  pressure  on  the  conduit  outside  the  tunnel,  it  was  essential 
to  stop  the  leakage  in  the  pipe  lining  of  the  tunnel,  and  a  plan  has  been 
devised  by  H.  N.  Savage,  M.  Am.  Soc.  C.  E.,  consulting  engineer  of  the 
company,  to  do  this  by  means  of  threaded  "  patch-bolts,"  tapped  into  the 
joints  at  intervals  of  3  inches,  thus  drawing  the  plates  together.  When 
this  is  done  cement  grout  will  be  pumped  into  the  cavities  at  one  of  the 
bolt-holes,  an  inside  band  will  be  inserted  covering  the  heads  of  the  patch- 
bolts,  and  the  space  filled  with  cement.  It  is  expected  that  the  device  will 
prove  successful.  At  the  upper  end  of  the  tunnel  a  balanced  valve  will 
control  the  admission  of  water,  and  additional  control  will  be  supplied  by  a 
gate-valve  in  the  pipe  at  the  tunnel-outlet,  and  a  gate-valve  operated  from 
the  shaft  at  the  junction  of  the  large  and  small  sections  of  the  tunnel. 
The  location  of  this  tunnel-outlet  through  the  hill  saved  a  mile  or  more  of 
pipe-line  through  the  canyon  from  the  dam,  although  the  latter  might  have 


32  HKSEliVOIUH  FOn  IRRIGATION,   WATKJt-POW/^JIl,  ETC. 


been  clieaper.  The  inaiu  conduit  from  the  reservoir  to  San  Diego  will  con- 
sist of  steel  and  wood-stave  pipe,  from  which  the  intermediate  lands  will  be 
supplied. 

The  Barrett  Dam. — 'J'he  middle  one  of  the  chain  of  three  great  reservoirs 
under  constraction  by  the  Southern  California  Mountain  Water  Company 
is  located  about  40  miles  southeast  of  San  Diego,  and  about  0  miles  north 
of  the  Mexican  boundary,  at  an  altitude  of  about  IGOO  feet.  It  occupies  a 
singularly  valuable  strategic  position,  as  it  is  the  lowest  feasible  reservoir- 
site  on  the  stream  from  which  water  can  be  conveyed  by  gravity  conduits 
without  passing  through  foreign  territory.  It  is  also  at  the  lowest  elevation 
from  which  water  can  be  distributed  to  the  most  valuable  mesa  lands 
adjacent  to  the  coast,  and  at  the  same  time  it  is  low  enough  on  the  stream 
to  receive  the  run-otf  from  the  greatest  area  of  mountain  watershed  avail- 
able for  any  reservoir  in  southern  California.  This  area  is  about  250  square 
miles.  The  precipitous  and  rocky  character  of  this  watershed  insures  a 
maximum  average  run-off  and  catchment  in  years  of  normal  precipitation. 

The  dam-  and  reservoir-site  were  acquired  by  the  San  Miguel  Water 
Company,  a  local  organization,  in  1889,  and  subsequently  transferred  to  the 
Jamacha  Irrigation  District,  organized  under  the  Wright  Law  of  California, 
for  the  consideration  of  $105,000  of  the  bonds  of  the  district,  the  purchase 
including  560  acres  of  land  and  certain  water-rights.  The  district  has 
taken  no  steps  to  construct  the  dam  and  conduit  by  which  alone  the 
property  would  have  value,  other  than  to  contract  with  the  Southern 
California  Mountain  Water  Company  for  its  water-supply,  and  the  latter  is 
now  engaged  in  constructing  the  dam.  In  1897  the  company  erected  a 
masonry  dam,  shown  in  Fig.  17,  72  feet  in  height  from  its  base,  which  is 
22  feet  below  the  stream-bed,  to  its  top  50  feet  above.  This  structure  rests 
on  solid  granite  bed-rock  throughout,  and  is  14  feet  thick  at  bottom,  5  feet 
at  top,  and  about  30  feet  long  on  the  crest.  This  was  to  be  used  simply  as 
a  pick-up  weir  to  divert  water  into  the  Dulzura  pass  conduit.  Subsequently 
it  was  decided  to  build  a  storage  dam,  similar  in  plan  to  that  of  the  Lower 
Otay,  to  an  extreme  height  of  175  feet,  and  a  new  location  was  chosen 
about  1000  feet  further  down  stream,  where  rock  could  be  more  con- 
veniently obtained  for  a  rock-fill  structure.  Here  a  new  masonry  dam  was 
built  in  1898,  reaching  to  bed-rock  in  the  stream-bed  and  extending  about 
35  feet  above,  upon  which  to  begin  the  sheet-steel  core  of  the  rock-fill 
The  dimensions  were  as  follows: 

Length  on  top   .  115  feet. 

Thickness  at  base   30  " 

Thickness  at  top   13  " 

Its  cubical  contents  are  3100  cubic  yards,  and  there  were  consumed  in  its 


LIBRARY 

UNIVERSITY  /mmi 


BOCK-FILL  DAMS. 


35 


construction  1777  barrels  of  cement.  An  outlet  tunnel,  8x8  feet  in  size, 
600  feet  long,  has  been  excavated  in  solid  rock  on  the  right  bank,  at  a 
height  of  80  feet  above  the  stream,  which  is  the  beginning  of  the  tunnel 
conduit  to  Dulzura  Pass.  Actual  work  upon  the  rock-fill  portion  of  the 
dam  has  not  yet  began,  and  it  is  possible  that  the  plans  may  yet  be  recon- 
sidered and  a  masonry  dam  sabstituted  for  the  rock-fill,  out  of  deference  to 
the  torrential  character  of  the  stream  in  seasons  of  exceptional  rainfall,  and 
the  possible  risk  involved  in  a  rock-fill  on  such  a  stream  during  construc- 
tion and  subsequently.  The  vast  importance  of  this  structure  as  the  key 
to  the  entire  system,  not  only  for  storage  but  for  the  diversion  of  water, 
doubtless  emphasizes  the  necessity  for  unquestionable  stability,  and  suggests 
the  wisdom  of  relying  upon  masonry.  It  cannot  be  claimed  for  rock-fill 
dams  that  they  are  inherently  superior  to  masonry  or  concrete  structures  of 
heavy  gravity  section,  and  they  are  only  to  be  preferred  as  a  substitute 
where  natural  conditions  render  them  very  much  cheaper,  and  hence  prac- 
ticable for  use  in  cases  where  the  greater  cost  of  masonry  would  be  prohibi- 
tive. 

Watershed. — The  tributary  watershed  ranges  in  altitude  from  1600  to 
6000  feet,  and  probably  averages  3600  feet.  The  mean  precipitation  on  this 
shed  may  ordinarily  be  expected  to  be  from  10  to  20  inches  greater  than 
that  of  San  Diego,  from  the  natural  increase  due  to  altitude,  and  in  some 
years  it  may  be  30  to  35  inches  greater.  The  mean  precipitation  of  San 
Diego  for  40  years  from  1850  to  1806  wag.  9.86  inches,  ranging  from  3.02 
inches  in  1863  to  27.59  inches  in  1884'  To  fill  the  reservoir  to  the  175- 
foot  contour  will  require  47.970  acre-feet  (20,900,000,000  cubic  feet)  which 
would  be  supplied  by  an  average  run-off  of  3.6  inches  from  the  watershed. 
Under  unfavorable  conditions  this  depth  of  run-off  would  be  expected  from 
an  annual  rainfall  of  24  inches,  and  may  at  times  be  the  product  of  but  15 
inches'  precipitation,  depending  largely  upon  the  distribution  of  the  storms, 
and  the  frequency  with  which  they  succeed  each  other.  In  years  like  1884 
or  1895  the  run-off  may  be  as  great  as  ten  times  the  capacity  of  the 
reservoir,  and  the  maximum  spillway  capacity  to  be  provided  may  reach 
40,000  second-feet. 

Morena  Rock-fill  Dam. — The  third  great  reservoir  of  the  Southern 
California  Mountain  Water  Company  is  located  10  miles  east  of  the  Barrett 
dam,  on  one  of  the  two  streams  that  unite  just  above  Barrett,  at  an  altitude 
of  3100  feet  above  sea-level.  It  is  50  miles  from  San  Diego,  and  7  miles 
north  of  the  international  boundary.  The  dam  is  a  rock-fill  structure, 
placed  in  a  narrow  canyon,  cut  through  massive  granite  cliffs  that  tower 
hundreds  of  feet  high,  on  the  brink  of  a  precipitous  fall  or  cataract,  where 
the  stream  takes  a  plunge  of  1200  to  1300  feet  in  a  mile  of  distance.  This 
canyon  is  filled  with  enormous  bowlders  throughout,  and  at  the  site  of  the 
dam  the  narrow  fissure  eroded  by  the  stream  was  found  to  be  more  than 


36       nKSERVoms  for  irrioation,  wATKR-powiui,  ma 

100  feet  deep  below  the  stream-bed.    Fig.  18  is  a  view  taken  of  the  dam- 
site  looking  up  stream,  and  well  illustrates  the  character  of  the  rock-masses 
filling  the  gorge.    The  tree  growing  at  the  right  of  the  picture  is  on  the 
line  of  the  masonry  toe-wall.    This  wall  was  carried  down  to  the  bottom  of 
the  fissure,  112.5  feet  below  the  general  stream-bed  at  that  point.  This 
wall  is  at  the  upper  toe  of  the  rock-fill,  and  is  30  feet  thick  at  the  bottom, 
where  the  width  between  solid  walls  was  but  4  feet  for  a  height  of  12  feet. 
The  widest  part  of  the  fissure  was  16  feet,  and  at  the  zero  contour  it  was 
80  feet  wide.    At  this  point  the  thickness  of  the  masonry  was  made  20  feet. 
It  was  carried  up  30  feet  higher,  where  the  thickness  is  12  feet.    The  top 
of  the  wall  is  shown  in  the  view  of  the  partially  finished  dam  (Fig.  19)  just 
above  the  water-line.    The  upper  toe  of  the  rock-fill,  which  will  be  finished 
on  a  slope  of  li  to  1,  will  reach  to  the  top  of  this  toe-wall,  and  will  be 
covered  with  5  feet  of  Portland  cement,  uncoursed  rubble  masonry,  over 
which  it  was  intended  to  lay  a  sheet  of  asphalt  concrete,  12  inches  thick  at 
base  and  4  inches  thick  on  top,  extending  into  a  groove  moulded  in  the 
wall,  5  feet  in  depth.    The  plan  for  using  asphalt  concrete  has  been 
abandoned  recently  and  some  other  material  will  be  substituted.    The  rock- 
fill,  as  shown  by  this  view,  is  about  80  feet  high  above  the  wall. 

The  canyon  walls  are  of  clean,  hard  granite,  singularly  free  from  fissures 
and  seams.  The  width  between  them  is  but  80  feet  at  the  stream-bed  and 
470  feet  at  the  height  of  160  feet  above.  The  sides  thus  have  a  slope 
steeper  than  1  to  1,  or  about  41°  from  the  vertical.  Had  the  planes  of  the 
side  slopes  continued  beneath  the  surface  the  maximum  depth  to  bed-rock 
would  have  been  but  30  feet  instead  of  112,5  feet  where  it  was  found.  The 
situation  is  a  favorable  one  for  any  type  of  dam,  except  earth,  and  especially 
favorable  for  a  masonry  structure,  although  the  freighting  of  cement  to  the 
site  would  have  made  that  class  of  work  more  costly  than  at  the  Lower 
Otay.  Work  was  begun  in  the  summer  of  1896,  and  by  the  fall  of  the  fol- 
lowing year  the  rock-fill  had  reached  a  height  of  80  feet  above  the.  top  of 
the  toe-wall,  when  work  was  suspended.  The  ultimate  height  to  which  the 
dam  is  designed  to  be  carried  is  160  feet,  to  hold  a  maximum  depth  of  150 
feet  of  water,  and  impound  46,733  acre-feet  (20,360,000,000  cubic  feet). 
The  volume  of  rock  in  the  structure,  computed  on  slopes  of  1  to  1  on  the 
face,  and  1^  to  1  on  the  back,  will  be  approximately  400,000  cubic  yards. 
If  the  face  is  given  a  slope  of  1^  to  1,  the  volume  will  considerably  exceed 
this  amount.  The  thickness  at  base  is  over  800  feet,  while  the  extreme 
height  of  rock-fill  from  the  lower  toe  down  the  canyon  will  be  in  excess  of 
250  feet.  Large  blasts  were  employed  in  loosening  the  rock  for  the  dam  in 
a  similar  manner  to  the  method  used  at  the  Otay  dam,  with  the  exception 
that  the  quarries  were  located  on  each  side  of  the  canyon  above  the  top  of 
the  dam,  in  such  position  that  much  of  the  rock  was  thrown  down  in  place 
thereby  and  did  not  subsequently  require  removal.^  Bowlders  weighing 


LIBRARY 


ROCK-FILL  DAMS, 


39 


hundreds  of  tons  were  thus  deposited  in  the  bed  of  the  canyon  and  on  its 
slopes. 

The  first  blast  of  100,000  lbs.  of  powder,  exploded  December  26,  1896, 
was  estimated  to  have  moved  75,000  cabic  yards.  A  second  blast,  fired  five 
days  later,  with  80,000  lbs.,  did  good  execution,  and  on  March  24,  1897, 
the  explosion  of  70,000  lbs.  is  reported  to  have  loosened  100,000  tons. 

The  machinery  assembled  for  the  constraction  is  said  to  have  cost 
$175,000.  Two  lines  of  Lidgerwood  cableway  span  the  chasm  at  a  height 
of  400  feet,  operating  from  the  quarries  on  either  side.  These  cableways 
are  attached  to  heavily  ballasted  cars,  supported  on  three  lines  of  railway- 
track  on  either  side,  with  a  range  of  movement  of  100  feet  each,  parallel 
with  the  axis  of  the  dam.    Powerful  derricks  of  the  most  improved  types 


^■^^^^S^^^  ^^^^ 


Pig.  19.— Morena  Rock  fill  Dam  in  Process  of  Construction.    Showing  Top 
OF  Toe-wall  above  the  Water-line. 

have  been  placed  in  convenient  position,  and  no  less  than  twenty  hoisting- 
engines  have  been  assembled  for  the  work. 

Outlet. — The  water  is  to  be  drawn  from  the  reservoir  through  a  tunnel, 
600  feet  long,  cut  in  the  granite  on  the  south  side  at  the  30-foot  contour, 
the  dimensions  of  which  are  8  x  8  feet.  This  tunnel  is  to  be  controlled  by 
a  series  of  balanced  valves  to  be  placed  at  the  reservoir  end,  while  the  water 
is  to  be  discharged  into  the  canyon  and  flow  down  the  channel  to  the 
Barrett  reservoir  below. 

,  Watershed.~The  area  of  drainage  intercepted  by  the  dam  is  130  square 
miles,  or  rather  more  than  half  of  that  tributary  to  the  Barrett,  of  which  it 
is  a  part,  and  ranging  in  altitude  from  3200  to  6000  feet,  averaging  about 
4000  feet.  Both  reservoirs  cannot  be  expected  to  fill  every  year,  although 
there  are  frequent  seasons  when  the  run-off  will  surpass  the  capacity  of  all 


40         BESKRVOIRS  FOR  IRRIOATION,  WATER-POWKR,  ETC. 


tliree  reservoirs  in  the  system.  I^y  providing  ample  storage  and  holding' 
over  a  large  surplus  every  year,  the  maximum  duty  can  be  obtained  from 
the  tributary  streams. 

Conditions  of  Construction. — The  dam  is  being  built  under  a  contract 
with  the  city  of  San  Diego  by  which  the  company  undertakes  to  deliver 
1000  miner's  inches  continuous  flow  (12,900,000  gallons  daily),  at  a  point 
designated  as  the  "Meter-house  Site,"  about  11  miles  southeast  of  the 
nearest  limits  of  the  city,  for  the  sum  of  1727,000.  This  is  to  be  accom- 
plished by  the  conduit  from  the  Barrett  dam  to  Dulzura  Pass,  9.5  miles  in 
length,  which  is  to  have  a  large  surplus  capacity  for  conveying  water  to  the 
Otay  reservoir,  and  by  a  continuation  of  this  conduit  of  smaller  capacity  a 


Fig.  20.— Morena  Rock-fill  Dam,  showing  a  Portion  of  Toe- wall  under 

Construction, 


distance  of  26  miles  further,  from  the  Dulzura  Pass  to  the  Meter-house 
Site. 

Between  the  outlet  level  and  the  120-foot  contoar  the  reservoir  has  a 
capacity  sufficiently  in  excess  of  the  agreed  amount  required  to  supply  1000 
inches  flow  for  one  year  to  cover  probable  loss  by  evaporation,  and  under 
the  contract  so  much  of  the  reservoir  up  to  the  120-foot  contour  is  to  be 
conveyed  by  deed  to  the  city,  while  all  the  land  above  the  120-foot  level  is 
to  be  reserved  by  the  company,  together  with  the  privilege  of  building  the 
dam  to  a  greater  height,  thus  storing  water  for  its  own  use  and  for  sale  to 
other  parties  on  top  of  the  city's  reservoir.  The  addition  of  30  feet  will 
increase  the  capacity  200^,  giving  the  company  about  30,000  acre-feet  of 
water.    The  watershed  area  above  the  dam  as  before  stated  is  about  130 


ROCK-FILL  DAMS. 


41 


square  miles,  from  which  a  run-off  of  20^  of  32  inches  of  rainfall  would 
suffice  to  fill  the  reservoir. 

Work  upon  the  reservoir  has  been  suspended  pending  the  outcome  cf 
protracted  14tigation  over  the  validity  of  the  contract  between  the  city 
council  of  San  Diego  and  the  water  company,  and  the  validity  of  the  city 
bonds  voted  for  the  water-works.*  Meantime  it  is  understood  that  the 
Biirrett  dam  is  to  be  completed,  and  the  conduit  to  Dulzura  Pass  and 
beyond,  by  which  the  company  will  be  enabled  to  utilize  its  system  for  irri- 
gation independently  of  the  water-supply  of  San  Diego. 

The  entire  system  is  the  most  comprehensive  storage  enterprise  yet  pro- 
jected in  California  for  the  utilization  of  water  that  normally  flows  to  the 
sea  unemployed  and  useless.  Its  completion  will  be  an  important  factor 
in  the  development  of  a  portion  of  the  frostless  area  of  southern  California. 

The  Upper  Otay  Dam. — This  structure,  which  is  a  part  of  the  general 
system  just  described,  is  on  the  West  Fork  of  Otay  Creek,  and  is  at  such 
an  elevation  that  the  high-water  line  of  the  Lower  Otay  reservoir  will  touch 
the  base  of  the  dam  of  the  Upper  one.    The  dam-site  is  in  a  porphyry-rock 


Fig.  21.— Reservoirs  near  San  Diego,  California. 


gorge,  where  the  width  between  walls  at  the  stream-bed  is  but  20  feet. 
The  supporting  hills  fall  away  quite  rapidly,  however,  so  that  at  the  60-foot 
contour  the  width  is  216  feet,  and  at  the  120-foot  contour  it  is  1060  feet. 
The  dam  has  been  started  as  a  masonry  structure  and  carried  to  a  height  of 
34  feet,  but  as  the  watershed  directly  tributary  is  but  8  square  miles,  and 
the  capacity  of  the  reservoir  quite  limited  (15,342  acre-feet),  as  compared 
with  the  Lower  Otay,  its  completion  and  nltilization  as  a  storage-reservoir 
will  be  independent  of  its  own  local  water-supply.  The  masonry  wall 
already  laid  has  a  length  at  bottom  of  bat  12  feet,  and  is  but  75  feet  long 

*  This  contract  lias  recently  been  declared  void,  the  Supreme  Court  of  California 
Laving  decided  that  the  election  for  the  bonds  voted  by  the  City  was  illegal  and  invalid. 


42  liESERVOIRS  FOR  IRRIGATION,   WATKR-POWKB,  ETC. 

on  its  present  crest.  The  height  is  to  be  materially  increased  in  the  near 
future  if  the  plans  of  the  company  are  not  changed,  and  it  may  become  a 
structure  of  considerable  magnitude. 

Chatsworth  Park  Rock-fill  Dam.— A  structure  of  more  than  common 
interest  as  an  example  of  "  how  not  to  do  it"  was  erected  on  Mormon 
Canyon,  in  the  westerly  part  of  San  Fernando  Valley,  Los  Angeles  Co., 
California,  near  the  station  of  Chatsworth  Park,  in  the  winter  of  1895-90, 
for  impounding  water  for  irrigation  and  to  serve  as  a  diverting-dam  for  a 
conduit  to  carry  the  flood-water  of  the  stream  to  a  secondary  reservoir  of 


Fig.  22,— Upper  Otay  Dam,  Foundation  Masonry. 


much  larger  capacity  a  short  distance  away  to  the  south.  Two  failures  of 
earth  dams  erected  at  the  same  site  had  already  occurred  prior  to  the  build- 
ing of  the  dam  in  question,  both  having  been  overtopped  and  carried  away 
by  reason  of  insufficient  spillway  capacity.  The  last  one  was  swept  out 
shortly  before  beginning  work  on  the  rock-fill,  chiefly  as  the  result  of  bad 
management.  The  spillway  had  been  filled  with  sand-bags  to  make  the 
reservoir  hold  a  little  more,  and  when  the  flood  came  there  was  no  one  at 
hand  to  remove  them.  When  the  attendant  finally  arrived  the  sluice-gate 
was  stuck  fast  and  could  not  be  opened,  and  before  any  relief  was  afforded 
the  water  rose  over  the  top  of  the  dam  and  washed  it  away,  although  it  was 
a  well-built  structure. 

The  rock-fill  dam  was  built  41.33  feet  high  above  the  creek-bed,  10  feet 


ROCK-FILL  DAMS. 


43 


i\^i(le  on  the  top,  with  sides  sloping  at  an  angle  of  60°,  above  and  below 
alike,  or  1  vertical  to  0.57  horizontal,  which  gave  a  base  width  of  60  feet. 
The  length  on  bottom  is  100  feet,  and  at  top  159  feet;  cubical  contents, 
6.025  cubic  yards;  area  of  water-face  7700  square  feet,  covered  with 
Portland-cement  concrete  from  8  inches  thick  at  top  to  16  inches  at  bottom. 
The  rock  used  for  the  fill  is  a  soft  sandstone,  quarried  on  the  line  of  the 
■dam  at  one  end,  500  feet  away,  and  75  feet  to  100  feet  higher  than  the  top 
-of  the  dam.    The  quarry -face  was  30  to  40  feet  high.    A  light  trestle  was 
built  on  a  sharp  incline  from  the  quarry  to  and  across  the  dam,  and  a  cable, 
passing  over  a  drum  or  pulley  at  top  and  with  a  car  attached  to  each  end, 
was  the  means  employed  for  transportation,  the  loaded  cars  fetching  np  the 
empty  ones.    The  material  was  dumped  in  place  promiscuously  and  without 
selection.    Some  of  it  disintegrated  and  crumbled  into  sand  when  blasted, 
hammered,  or  dropped  from  a  few  feet  in  height,  and,  as  everything 
loosened  in  the  quarry  was  put  into  the  fill,  the  proportion  of  sand  and 
earth  is  very  large  and  the  natural  angle  of  repose  of  the  mass  is  much 
flatter  than  that  of  rock  alone,  and  flatter  than  the  slopes  proposed  by  the 
plans.    The  specifications  required  the  slopes  to  be  laid  up  two  feet  in 
thickness  as  a  dry  wall  of  nncoursed  rubble,  but  this  was  done  in  such  an 
indifferent  manner  that  within  two  weeks  after  the  contractor  had  moved 
off  the  work  more  than  three-fourths  of  the  lower  face-wall  fell  or  slid 
down,  followed  by  some  of  the  embankment  behind  it  so  as  to  leave  the 
concrete  facing  unsupported  and  its  under  side  exposed  to  view  for  several 
feet  from  the  top  of  the  dam.    The  dam  was  not  of  much  value  for  water- 
tightness,  as  it  leaked  considerably  with  but  10  feet  of  water  behind  it. 
The  work  was  done  by  contract,  at  a  total  cost  of  about  $9000,  part  of  which 
was  payable  in  land.    After  the  work  was  done  the  contractor  took  advan- 
tage of  the  failure  of  the  company  to  comply  with  the  California  law 
requiring  contracts  to  be  recorded  to  make  them  valid,  and  brought  suit  to 
recover  a  greater  amount  than  the  contract  price.    He  succeeded  in  getting 
a  jury  to  give  judgment  for  about  40^  additional,  while  the  owners  have 
been  obliged  to  reconstruct  the  dam.    This  was  begun  on  the  plan  illus- 
trated in  Fig.  23,  the  lower  slope  being  hand-laid  to  a  thickness  of  4  feet, 
and  covered  with  a  jnasonry  slope-wall  6  feet  thick,  although  the  work  is 
still  incomplete.    This  is  believed  to  be  the  first  case  on  record  of  a  dam 
falling  down  before  the  water-pressure  had  been  applied  to  it. 

The  watershed  area  above  the  dam  is  about  15.5  square  miles,  from  1000 
to  3800  feet  in  elevation,  from  which  maximum  floods  of  700  to  800  second- 
feet  may  be  expected — sufficient  to  fill  the  reservoir  in  three  or  four  hours, 
as  the  capacity  is  not  in  excess  of  200  acre-feet. 

The  Castlewood  Dam,  Colorado.  —  The  Chatsworth  Park  dam,  just 
described,  bears  some  resemblance  to  the  Castlewood  dam  erected  on  Cherry 
€reek,  some  35  miles  above  Denver,  Colorado  (which  city  is  at  the  mouih 


44 


RESFAiVOim  FOR  lURIOATION,   WATKR-POWKll,  KTG. 


of  the  same  stream),  although  the  latter  striictare  is  a  much  more  success- 
ful engineering  work  and  of  greater  size  and  importance.  The  Castle- 
wood  dam  was  huilt  in  1890  by  the  Denver  Land  and  Water  Company,  for 
the  impounding  of  water  for  the  irrigation  of  some  16,000  acres  of  fertile 
mesa  land  lying  between  Cherry  Creek  and  the  South  Platte  River,  and 
extending  to  the  city  limits  of  Denver. 

The  area  of  watershed  above  the  dam  is  about  175  square  miles,  from 
which  the  run-off  after  severe  cloud-bursts  on  the  "divide"  sometimes 


a"Concrefe 


Fig.  23.— Sketch  of  Reconstruction  of  Chatsworth  Park  Rock-fill  Dam. 


reaches  or  exceeds  10,000  cubic  feet  per  second  for  a  short  time.  The 
reservoir  covers  about  200  acres,  and  has  a  capacity  of  4,000,000,000 
gallons,  or  about  12,280  acre-feet.  The  dam  is  a  rock-fill  with  a  masonry 
wall  on  the  upper  face,  while  the  lower  slope  is  covered  in  steps  of  2  feet 
with  large  blocks  of  stone  laid  in  cement  mortar,  the  general  slope  being  1 
to  1.  The  facing  wall  is  of  rough  rubble  masonry,  4  feet  thick,  standing 
on  a  slope  or  batter  of  1  to  10.  The  two  walls  are  joined  at  the  top  with  a 
coping  of  large  stones,  forming  the  crest  of  the  dam,  8  feet  in  width,  4  feet 
thick.  The  geological  formation  at  the  dam-site  is  peculiar.  The  floor  of 
the  reservoir  basin  is  covered  to  a  great  depth  with  hard,  blue  clay,  over- 
lying which  is  a  great  sheet  of  sandstone  and  conglomerate  rock  or 
"  pudding-stone  "  100  feet  or  more  in  thickness.  The  dam  was  founded 
on  the  clay,  and  the  facing-wall  was  carried  down  into  it  to  a  depth  of  6  to 


ROCK-FILL  DAMS. 


45 


22  feet.  The  lower  slope-wall  was  also  foanded  on  this  clay  at  a  depth  of 
10  feet  from  the  surface.  The  general  dimensions  of  the  stracture  are: 
length  at  top,  600  feet;  extreme  height  above  floor  of  reservoir,  70  feet; 
height  above  foundation  of  face-wall,  92  feet;  width  on  top,  8  feet.  The 
main  spillway  is  located  in  the  center  of  the  dam,  and  is  100  feet  long  by 
4  feet  deep.  An  auxiliary  spillway,  called  a  by-pass,  is  located  at  the  west 
end  of  the  dam,  and  is  40  feet  in  width.  The  total  spillway  capacity  thus 
provided  is  about  4000  second-feet,  while  the  outlet-pipes,  eight  in  number, 
each  12  inches  diameter,  have  a  combined  capacity  of  about  250  second- 
feet. 

A  "  water-cushion  "  has  been  provided  at  the  toe  of  the  dam,  to  receive 
the  impact  of  the  waste  water  pouring  over  the  structure  and  to  prevent 
erosion  of  the  toe.  This  is  25  feet  wide,  200  feet  long,  and  consists  of  a 
rock  pavement,  3  to  6  feet  deep,  heavily  grouted  at  the  top  with  cement 
mortar. 

The  face-wall  has  been  reinforced  by  an  embankment  of  earth  placed 
against  it,  and  covered  with  stone  riprap,  1  foot  thick.  This  embankment 
reaches  to  within  30  feet  of  the  top  of  the  dam  at  the  outlet-tower  near  the 
center,  and  rises  to  the  full  height  at  either  extremity.  The  outlet-tower 
is  a  rectangular  structure,  built  in  the  body  of  the  dam,  with  a  central 
opening  of  6  X  7.5  feet  reaching  to  the  top.  Into  this  the  eight  12-inch 
outlet-pipes  discharge  at  four  successive  levels,  6  feet  apart  from  the  base 
up,  the  gate-valves  being  placed  inside  the  tower.  From  the  base  of  the 
tower  the  water  discharges  into  the  creek  channel  through  a  36-inch  open 
pipe,  made  of  concrete  4  feet  thick,  surrounding  a  cement  pipe  of  standard 
dimensions.  The  water  is  picked  up  l^miles  below  the  storage-dam  by  a 
low  diverting-dam,  125  feet  long,  and  conveyed  through  40  miles  of  canals, 
with  maximum  capacity  of  75  second-feet,  to  the  lands  irrigated  and  to  an 
auxiliary  reservoir,  formed  from  a  natural  depression  in  the  plain.  This 
reservoir  has  a  surface  area  of  60  acres  and  a  capacity  of  700  acre-feet,  its 
maximum  depth  being  16  feet. 

The  construction  of  the  Castlewood  dam  was  attended  by  much  opposi- 
tion from  the  citizens  of  Denver,  who  were  apprehensive  of  its  safety  and 
severely  criticised  the  plan.  Unsuccessful  attempts  were  made  to  enjoin 
the  construction,  but  it  was  finally  permitted  to  be  completed  and  has  suc- 
cessfully withstood  all  floods  to  the  present  time.  The  facing-wall  has 
shown  no  sign  of  settlement,  but  the  main  embankment  settled  a  few 
inches,  sufficiently  to  produce  an  unsightly  crack  in  the  center  of  the  dam 
along  the  lower  line  of  the  face- wall.  The  coping-stones  were  subsequently 
relaid  to  true  line  again  and  no  subsequent  crack  has  developed.  The 
canals  and  reservoirs  have  cost  about  $425,000.  The  dam  was  planned  by 
A.  M.  Wells,  O.E.,  of  Denver,  with  Mr.  Alfred  P.  Boiler,  M.  Am.  Soc. 
C.  E.,  of  New  York,  as  consulting  engineer.    Fig.  24  (taken  tiom  Engineer- 


ROCK-FILL  DAMS. 


49 


ing  Record,  Dec.  24,  1898,  and  reprouaced  by  courtesy  of  tliat  journal) 
illustrates  the  construction  of  the  dam  in  plan,  section,  and  elevation. 

Pecos  Valley  Rock-fill  Dams,  New  Mexico. — Two  rock-fill  dams  with 
earth  facings  have  been  constructed  across  the  Pecos  Eiver,  in  the  Pecos 
Yalley,  New  Mexico,  which  have  boldly  and  successfully  exemplified  a  dis- 
tinct type  of  dam  that  is  considered  to  be  preferable  to  all  other  rock-fills 
where  the  proper  conditions  exist  and  suitable  materials  are  obtainable. 
One  of  these  dams  is  located  6  miles  and  the  other  15  miles  above  the  town 
of  Eddy,  N.  M.  They  were  built  by  the  Pecos  Irrigation  and  Improvement 
Company. 

Lake  Avalon  Dam. — The  lower  dam,  designated  locally  as  the  Lake 
Avalon  dam,  was  built  primarily  as  a  means  of  raising  the  level  of  water  of 
the  river  in  order  to  divert  it  into  a  canal  at  a  safe  height  above  the  reach 
of  maximum  floods,  and  at  the  same  time  to  equalize  the  flow  by  providing 


Fig.  25. — Sketch-map  of  Dam  at  Head  of  Pecos  Canal 


a  considerable  volume  of  storage  in  the  reservoir  thus  created.  The  present 
dimensions  of  the  dam  are  as  follows:  length  on  crest,  1135  feet;  maximum 
height,  48  feet;  outer  slope  of  rock-fill,  Ih  to  1;  width  of  rock  base,  106 
feet;  crown,  10  feet.  The  earth  facing  has  also  a  crown  width  of  10  feet, 
making  the  total  width  20  feet  on  top.  The  slope  of  the  earth  embank- 
ment that  is  built  against  the  rock-fill  is  3  to  1,  which  is  covered  with  a 
revetment  of  loose  stone  2  to  3  feet  thick  for  wave  protection.    The  rock- 


50 


BESERVOIRH  FOR  JHHIOATION,    WATER-POWER,  ETC. 


fill  before  the  addition  of  the  earth  facing  is  illustrated  by  Fig.  2(5,  a  view 
taken  during  construction.  Fig,  27  is  a  view  of  the  finished  dam,  taken  in 
1892.  The  grade  of  the  maiti  canal  leading  out  from  the  dam  on  the  east 
side  of  the  valley  is  10  feet  above  the  base  of  the  dam,  and  is  excavated 
in  limestone  to  a  maxinuini  depth  of  38  feet.  Fig.  28  is  a  view  of  the  main 
canal  and  headgates,  taken  from  the  lower  side. 


Fig.  26.— Lake  Avalon  Dam.    Rock-fill  in  Process  of  Construction. 


The  dam  was  in  service  until  August  3,  1893,  when  it  was  ruptured  by 
a  flood-wave  that  was  in  excess  of  the  spillway  capacity— the  old  story  con- 
nected with  dam  failures.  The  water  poured  over  its  crest,  and,  as  this 
style  of  dam  is  not  calculated  to  withstand  such  an  overflow,  it  speedily 
washed  out  a  breach  to  the  bed-rock  over  300  feet  in  length.  This  was 
immediately  repaired  and  built  5  feet  higher,  at  a  total  cost  of  $86,000. 
The  capacity  of  the  open  spillway  at  the  west  end  of  the  dam  was  increased 
by  widening  it  from  200  feet  to  a  width  of  240  feet,  and  by  cutting  it  3  feet 
deeper,  making  it  begin  to  discharge  while  the  water  is  15  feet  below  the 
crest.  A  second  spillway  in  rock  was  cut  about  half  a  mile  to  the  west  of 
spillway  No.  1,  having  a  length  of  300  feet.  In  addition  to  these  discharge- 
channels  the  main  canal  below  the  dam  is  so  arranged  that  surplus  water 
will  begin  to  slop  over  its  banks  at  a  height  of  13  feet  above  the  bottom  of 
the  canal,  over  a  length  of  about  200  feet.  By  opening  the  headgates  and 
partially  closing  the  secondary  gates  across  the  canal  below,  this  slop-over 
can  be  given  a  large  capacity  of  discharge.    Ordinarily,  however,  the 


BOCK-FILL  BAMS. 


51 


water-level  ia  this  section  of  canal  is  maintained  to  a  depth  of  over  20  feet, 
above  the  floor  of  the  canal  by  a  series  of  thirty-one  gates  placed  on  the  side 
of  the  canal,  parallel  to  it,  and  across  the  spillway.  These  gates  are  hinged 
at  the  sides,  and  are  each  5  feet  ^  inch  wide  by  7  feet  2  inches  high. 
They  can  be  opened  in  an  emergency  almost  instantly  by  the  stroke  of  a 


Fig.  27. — Lake  Avalon  Dam,  Pkcos  Rivek,  New  Mexico.    Showing  the  Crest 
OF  Completed  Dam  and  Spillway  Discharging. 


hammer  npon  a  latch-releasing  bar  at  each  gate,  when  the  pressnre  forces 
them  to  fly  open  like  a  door.  The  opening  can  be  closed  above  the  gates 
by  flash-boards,  permitting  the  closing  and  latching  of  the  doors.  (See 
Fig.  29,  taken  from  Engineerwg  Mtvs,  Sept.  17,  1896.)  The  total 
capacity  which  the  spillways  now  have  is  estimated  at  33,000  second-feet, 
while  the  water-level  is  still  below  the  top  of  the  dam. 

The  original  cost  of  the  dam  was  about  190,000,  and  the  reconstruction 
was  therefore  bat  little  less  than  the  first  cost. 

Mr.  H.  H.  Cloud,  formerly  of  the  Colorado  Midland  Railroad,  was  the 
chief  engineer  of  the  dam,  with  Mr.  E.  S.  Nettleton  acting  as  consulting 
engineer,  and  Mr.  Louis  D.  Blauvelt  as  principal  assistant.  Mr.  Cloud 
ascribes  the  cause  of  the  overtopping  of  the  dam  to  the  fact  that  the  spill- 
ways were  choked  by  the  debris  from  bridges,  together  with  the  bodies  of 
drowned  cattle  brought  down  by  the  river.  Another  account  states  that 
the  gate-keeper  and  his  assistants  were  in  Eddy  at  the  time,  indulging  in  a 
drunken  spree,  and  did  not  start  for  the  dam  until  the  only  bridges  across 


52 


liESBRVOIUS  FOR  IRIUQATION,   WATKR-POWKR,  KTG. 


the  river  were  washed  away,  and  they  could  not  cross.  When  they  finally 
secured  boats  for  crossing  and  reached  the  dam  just  before  the  disaster, 
they  were  unable  to  open  the  waste-gates  because  of  a  defect  in  construc- 
tion, since  remedied.  It  was  believed  that  if  the  lateral  waste-gates  along 
the  canal  had  been  opened  when  the  flood-wave  first  reached  the  dam,  the 
relief  thus  afforded  would  have  avoided  the  disaster.  No  loss  of  life  was 
reported  as  a  result  of  the  flood,  and  but  little  property  was  damaged. 

The  reservoir  capacity  of  Lake  Avalon  from  the  floor  of  the  canal  to  the 
spillway-level  is  about  6300  acre-feet. 

Irrigation  from  Reservoir. — The  main  canal,  on  the  east  side  of  the 


Fig.  28. — Canal  Headgates,  Lake  Avalon  Dam. 


river,  has  a  capacity  of  1300  second-feet  for  3.2  miles,  to  the  junction  of 
the  Southern  and  East  Side  canals,  the  width  on  bottom  being  15  feet, 
depth  7  feet,  and  grade  1.5  feet  per  mile.  The  Southern  Canal  from  the 
junction  down  for  9  miles  has  a  capacity  of  (580  feet.  On  this  section  the 
canal  is  carried  across  the  river  from  the  east  side  to  the  west,  in  a  flume 
468  feet  long,  25  feet  wide,  6  feet  deep,  supported  on  high  trestle  bents. 
The  approaches  consist  of  embankments,  or  "  terre  pleins,"  with  maximum 
height  of  over  30  feet.  The  second  section  is  4.2  miles  long  with  460 
second-feet  capacity.  The  third  section  is  2  miles  with  385  second-feet 
capacity,  followed  by  21.6  miles  in  which  the  maximum  capacity  is  215 
second-feet— the  bottom  width  being  14  feet  and  the  depth  4  feet.  The 
total  length  is  40  miles,  although  operated  for  but  31  miles. 


ROCK-FILL  BAMS. 


Fig.  29. — Quick-opening  Gates  in  Spillway  op  Lake  Avalon  Reservoir,  Pecos 

VALIiEY,  N.  M. 


54 


RESERVOTRS  FOR  IRRIGATION,  WAlEJi-POWKR,  ETC. 


The  East  Side  Canal  is  19.  G  miles  long,  with  maximum  capacity  of  224 
second-feet.  The  upper  4  miles  only  are  used,  and  but  IG  miles  are  avail- 
able for  service.  The  entire  canal  system  has  cost  about  $400,000  in  all. 
The  area  irrigated  from  these  canals  in  1897  was  as  follows: 

Southern  Canal   13,000  acres. 

East  Side    "    2,500  " 

Total   15,500  " 

The  area  commanded  by  these  two  canals  is  110,000  acres,  of  which 
{)0,000  acres  are  under  the  main  Southern  Canal. 

Water-tiglitness  of  Lake  Avalon  Dam. — The  dam  is  apparently  free 
from  direct  leakage  through  it,  although  water  stands  in  a  pool  at  the  base 


Fig.  31. — Sketch-map  of  Pecos  Valley  Canals. 


of  the  dam,  which  is  believed  to  come  from  springs,  issuing  from  the  rock. 
From  the  dam  down  for  several  miles  there  are  springs  of  large  volume 
coming  out  on  the  river-banks,  whose  total  flow  at  the  stone  dam  at  Eddy, 
as  measured  by  the  writer  in  October,  1897,  was  approximately  90  second- 
feet.  Since  the  construction  of  the  reservoir  these  springs  are  said  to  be 
increasing  in  number  and  volume.  The  largest  one,  flowing  5  to  G  second, 
feet,  broke  out  in  a  new  place  in  1896,  some  3  miles  below  the  dam- 
Distinct  swirls  and  miniature  maelstroms  have  been  observed  on  the  surface 
of  both  reservoirs,  from  which  it  is  surmised  that  water  in  considerable 
quantity  is  thus  lost  through  the  limestone  formation,  and  that  some  of  the 
springs  are  fed  from  this  souroe,  although  many  were  in  existence  prior  to 


LIBRARY 
UNlVtRSlTYoflUlNOU 


ROCK-FILL  DAMS. 


55 


the  building  of  the  dams.  This  "  leakage  "  does  not  in  any  manner  affect 
the  stability  of  the  dams  and  is  of  interest  chiefly  becaase  of  the  fact  that 
reservoirs  in  limestone  formation  are  generally  to  be  expected  to  be  subject 
to  similar  losses,  and  in  this  case  the  illustration  is  specially  well  marked 
and  visible. 

Lake  McMillan  Dam. — The  Upper  Pecos  River  reservoir  is  called  Lake 
McMillan,  and  is  formed  by  a  rock-fill  dam  of  the  same  general  type  as  the 
lower  one.  This  was  built  in  1893  under  Mr.  Louis  D.  Blauvelt  as  chief 
engineer.  The  dam  has  a  top  length  of  1685  feet,  and  a  maximum  height 
of  52  feet.  The  rock-fill  portion  was  made  14  feet  wide  at  top,  and  the 
earth-fill  6  feet  at  top — making  the  total  width  20  feet  as  in  the  lower 
dam,  the  slopes  being  the  same,  viz.,  1^  to  1  on  lower  and  3.5  to  1  on  upper 
side.  The  inner  face  of  the  rock-fill  against  which  the  earth  rests  has  a 
batter  of  0.5  to  1,  the  wall  being  laid  up  2  feet  thick  by  hand.  The  dam 
contains  102,400  cubic  yards  of  rock,  103,600  yards  of  earth,  3800  yards 
of  dry  retaining  wall,  and  6200  yards  of  riprap.  Its  cost  complete  is  stated 
to  have  been  $200,000.  An  auxiliary  embankment,  5200  feet  long,  10  feet 
wide  on  top,  18.8  feet  maximum  height,  with  slopes  of  1.5  to  1  and  3  to  1, 
and  containing  78,400  cubic  yards,  was  thrown  up  to  close  a  gap  in  the 
ridge  near  the  dam,  at  a  cost  of  110,000.  It  was  made  entirely  of  earth, 
paved  with  stone  for  a  portion  of  its  height  on  the  water-side.  When 
visited  by  the  writer  in  the  fall  of  1895,  and  again  in  1897,  the  dam  showed 
no  signs  of  leakage,  or  settlement,  or  any  form  of  weakness,  although  the 
reservoir  was  more  than  half  full.  ^Tiie  works  have  never  been  completed 
to  store  more  than  50,000  apre-feet,  crovering  an  area  of  5500  acres,  and  it 
will  be  necessary  to  construct  an  expensive  spillway  before  a  material  addi- 
tion can  be  made  to  the  volume  of  storage.  At  present  the  limit  of  storage 
is  17  feet  below  the  crest  of  the  dam,  above  which  the  water  passes  off 
through  a  gap  of  such  dimensions  as  to  carry  200,000  second-feet  before 
the  dam  could  be  overtopped.  The  plan  proposed  is  to  close  this  gap  with 
an  embankment  and  excavate  a  small  spillway  through  solid  limestone  on 
the  right  bank,  with  a  capacity  of  10,000  second-feet.  When  this  is  done 
the  water-level  will  be  raised  7  feet,  or  10  feet  below  the  crest,  and  the 
volume  of  storage  will  be  approximately  89,000  acre-feet,  covering  8331 
acres  of  surface. 

Outlet. — The  outlet  for  the  water  is  provided  by  means  of  a  canal  1100 
feet  long,  cut  through  solid  limestone  at  the  east  end  of  the  dam,  to  a 
maximum  depth  of  35  feet  below  the  crest.  This  is  controlled  by  massive 
wooden  headgates,  placed  on  the  line  of  the  dam,  six  in  number,  each 
4  feet  wide,  and  arranged  to  open  to  a  height  of  8  feet  by  screws.  Above 
these  openings  is  a  solid  wooden  bulkhead  filling  the  cross-section  of  the 
canal.  The  gates  are  6  inches  thick,  heavily  ironed.  The  water  issuing 
from  the  gates  passes  back  into  the  channel  of  the  river  and  thence  flows  to 


56 


llESKRVOIIiS  FOR  IllUIOATlON,   WATER- POWKR,  ETC. 


tlie  lower  reservoir.  The  canal  is  30  feet  wide,  and  required  the  excavation 
of  08,000  cubic  yards  of  rock,  solid  measurement,  all  of  which  was  used  in 
making  the  rock-lill  of  the  dam.    The  canal  headworks  cost  120,000. 

The  gates  have  a  discharging  capacity  of  4400  second-feet  when  the 
depth  of  water  over  the  floor  of  the  canal  is  but  18  feet,  and  considerably 
in  excess  of  this  amount  when  the  maximum  depth  of  25  feet  is  reached. 

This  type  of  rock-fill  dam  appears  to  possess  every  element  of  safety  so 
long  as  sufficient  spillway  is  provided  to  insure  them  from  being  overtopped. 
It  seems  particularly  well  adapted  to  the  conditions  found  in  the  Pecos 
Valley,  where  ledges  of  limestone  crossing  the  valley  appear  at  the  surface 
at  intervals,  affording  reliable  foundations  for  dams,  and  material  for  their 
construction;  where  an  abundance  of  suitable  earth  is  available  for  backing, 
and  where  dams  of  but  moderate  height  are  required  to  impound  large 
volumes  of  water.  Here  also  the  country  is  so  open  as  to  make  the  work 
easily  accessible  from  all  sides.  These  conditions  do  not  prevail  in  moun- 
tain canyons  as  a  rule,  and  in  such  localities,  where  construction  is  cramped 
for  room,  and  earth  is  scarce  and  hard  to  obtain,  some  other  material  for 
water-tight  facing  is  cheaper  and  preferable  to  earth.  For  the  special  con- 
ditions existing  where  they  were  built  these  dams  must  be  regarded  as  the 
best  that  could  have  been  planned. 

The  total  cost  of  the  two  reservoirs  and  the  canal  system  depending 
upon  them  was  1776,000,  an  average  of  about  $7  per  acre  for  the  110,000 
acres  of  land  commanded  by  the  canals.  The  same  company  has  built  an 
expensive  cut-stone  masonry  dam  for  power  purposes  at  the  town  of  Eddy, 
and  another  system  of  canals  near  the  town  of  Eoswell,  90  miles  further  np 
the  valley.  The  dam  is  ogee  in  section,  is  320  feet  long,  6  feet  high,  with 
abutments  20  feet  in  height,  and  cost  $22,000.  It  was  nearly  destroyed  by 
the  flood  of  1893,  when  the  Lake  Avalon  dam  gave  way,  and  was  subse- 
quently rebuilt.  A  canal  leading  from  it  on  the  east  side,  called  the 
Hagerman  Canal,  covers  about  5000  acres,  of  which  300  acres  are  irrigated. 
The  Northern  Canal,  near  Eoswell,  N.  M. ,  commands  59,000  acres,  of 
which  4000  acres  were  irrigated  in  1897.  The  canal  is  38  miles  long- and 
has  a  capacity  of  300  to  120  second-feet.  It  is  fed  directly  from  springs 
that  form  the  sources  of  the  Hondo  River. 

Wat 67' -supply. — The  area  of  watershed  drained  by  the  Pecos  River  above 
the  southern  boundary  of  New  Mexico  is  approximately  24,400  square 
miles,  having  a  maximum  elevation  of  about  11,892  feet.  After  leaving 
the  main  mountain  range  in  Northern  New  Mexico,  where  it  has  its  source, 
the  Pecos  enters  upon  a  tortuous  course  across  the  great  plateau  of  eastern 
New  Mexico  and  western  Texas,  skirting  to  the  eastward  of  the  foothills  of 
various  mountain  groups  and  isolated  peaks,  from  which  the  river  receives 
numerous  important  tributaries,  but  no  feeders  come  to  it  from  the  east  or 
the  region  of  the  "  Staked  Plains,"  whose  drainage  is  caught  in  shallow 


ROCK-FILL  DAMS. 


57 


pools,  or  sinks  into  the  limestone  formation  underlying  the  plains.  The 
maximum  flow  of  the  river  is  in  the  months  of  May,  June,  July,  and 
August  as  the  result  of  summer  rains,  more  than  75^  of  the  entire  precipi- 
tation of  the  year  falling  in  these  months.  Of  the  total  watershed  of  the 
Pecos  in  New  Mexico 

b'/o  has  a  mean  precipitation  exceeding  20  inches. 
50^    "      "  "  from  15  to  20  " 

20^    "      "  "  "    10  to  15  " 

25^    "      "  "         under  10 

These  data  are  taken  from  the  maps  of  the  U.  S.  Weather  Bureau,  pubs 
lished  in  1891,  from  which  the  following  data  as  to  mean  and  maximum 
precipitation  at  various  stations  within  the  Pecos  watershed  are  compiled : 


Station. 

Mean  Annual 
Precipitation. 
Inches. 

Maximum  Annual 
Precipitation. 
Inches. 

Elevation  above 
Sea-level. 
Feet. 

Fort  Stauton,  N.  M  

19.05 

28.70 

6154 

15.01 

27.27 

4300 

16.29 

16.70 

4500 

17.08 

27.82 

4800 

19.14 

28.14 

6750 

22.08 

6418 

15.32 
15.55 

3857 
3140 

Eddy,  "   

12.60 

The  estimated  discharge  of  the  stream  past  the  southern  boundary  of 
New  Mexico  was  approximately  700,000  acre-feet  in  1890,  1,300,000  acre- 
feet  in  1891,  and  1,000,000  acre-feet  in  1897.  In  1893  the  discharge 
exceeded  that  of  1891. 

The  minimnm  flow  above  Lake  McMillan  in  August,  1891,  was  202 
second-feet,  and  in  August,  1897,  225  second-feet.  The  maximum  of  1893 
was  estimated  at  42,500  second-feet.  The  total  flow  of  the  stream  is  thus  seen 
to  be  from  10  to  15  times  the  combined  capacity  of  the  two  reservoirs,  a  fact 
which  suggests  the  probability  of  a  somewhat  rapid  filling  of  the  reservoirs 
by  silt  carried  in  suspension,  and  also  emphasizes  the  necessity  of  ample 
spillway  capacity.  Furthermore  it  indicates  that  as  the  maximum  flow  is 
during  a  portion  of  the  irrigation  season,  the  reservoirs  do  not  require  to  be 
drawn  upon  except  at  the  lower  stages  of  the  river,  and  hence  their  duty 
promises  to  be  unusually  great.  The  great  surplus  of  unappropriated  water 
is  also  suggestive  of  the  need  for  additional  reservoirs,  some  of  whose  possi- 
bilities are  discussed  in  subsequent  pages. 


58  RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


Duty  of  Water  in  Pecos  Valley.— all  tlic  evidence  obtuiDable  it  is 
coiicliuled  tliiit  the  avenigo  consumpiioii  of  water  in  Pecos  Valley  the  first 
year  of  irrigation  is  4  to  5  acre-feet  per  acre,  and  the  ultimate  duty  after 
the  third  or  fourth  year  is  about  2  acre-feet  per  acre,  including  all  losses 
by  percolation,  leakage,  and  evaporation  in  the  canals.  Alfalfa  requires 
about  three-fourths  of  a  foot  at  the  first  watering  each  year,  and  yields  four 
crops,  needing  one  good  irrigation  of  half  a  foot  in  depth  at  each  cutting. 
Sugar-beets,  planted  in  June,  have  to  be  irrigated  three  or  four  times, 
besides  the  watering  needed  for  preparing  the  ground.  They  take  about 
one-third  of  a  foot  at  each  irrigation.  Small  grain,  sown  in  October,  is 
irrigated  once  before  sowing  and  once  in  November  or  December.  In 
March,  when  dry  winds  prevail,  the  surface  has  to  be  wetted  every  ten  days. 
In  all  six  or  seven  irrigations,  consuming  about  2  acre-feet  per  acre, 
are  required.  Orchards  need  three  to  six  irrigations.  The  labor-cost  of' 
irrigation  averages  about  15  cents  for  each  application,  and  the  cost  of 
water  is  $1.25  per  acre  for  the  entire  season,  regardless  of  the  volume  used. 

The  Walnut  Grove  Rock-fill  Dam,  Arizona. — Among  all  the  rock-fill 
dams  that  have  ever  been  built  or  projected  in  the  West  unquestionably  the 
slenderest  and  most  flimsily  constructed  was  that  erected  across  the 
Hassayampa  Eiver,  30  miles  south  of  Prescott,  Arizona,  in  1887-88,  the 
destruction  of  which  by  a  flood  on  the  night  of  February  22, 1890,  was  accom- 
panied by  the  loss  of  129  lives.  This  disastrous  result  was  predicted  when 
it  was  building  by  those  familiar  with  its  construction,  as  an  event  that  was 
likely  to  occar,  and  the  frightful  consequences  that  ensued  illustrate  and 
emphasize  the  necessity  and  importance  of  governmental  supervision  of  the 
plans  and  details  of  construction  of  all  structures  of  that  class,  either  by 
the  State  or  Federal  authorities.  It  should  never  have  been  permitted  to 
be  built  of  the  dimensions  given  to  it,  and  the  manner  of  its  building  was  a 
conspicuous  display  of  criminal  neglect  of  all  requisite  precautions  to  secure 
the  safety  of  any  dam,  and  particularly  one  of  the  rock-fill  type. 

The  dam  was  110  feet  high,  10  feet  thick  at  top,  138  feet  thick  at  base, 
about  150  feet  long  at  the  bed  of  the  stream,  and  400  feet  long  on  top. 
These  dimensions  would  not  have  been  excessive  for  an  overfall  dam  of 
solid  masonry  laid  up  in  Portland  cement,  but  for  a  rock-fill  the  slopes 
were  so  much  steeper  than  the  natural  angle  of  repose  of  loose  rock 
(20  horizontal  to  47  vertical  on  the  upper  side,  and  70  horizontal  to  108 
vertical  on  the  lower  side)  that  it  was  really  in  danger  of  settling  or  sliding 
down  to  flatter  slopes  without  the  assistance  of  water-pressure  against  it. 
That  it  did  not  do  so  was  solely  due  to  the  fact  that  the  faces  of  the 
embankment  were  laid  up  as  dry  walls,  each  having  a  thickness  of  14  feet 
at  base  and  4  feet  at  top,  the  center  being  a  loose  pile  of  random  stone 
dumped  in  from  a  trestle.    If  these  facing-walls  had  been  carefully  laid 


ROCK-FILL  DAMS. 


59 


with  large  stones,  on  level  beds,  and  an  adequate  spillway  provided  to  carry 
the  waste  water  around  the  dam  and  prevent  it  passing  over  the  top,  and  if 
proper  foundations  had  been  laid  for  the  entire  structure,  it  might  have 
been  standing  to-day.  In  a  paper  read  before  the  Technical  Society  of  the 
Pacific  Coast,  on  October  5,  1888,  eighteen  months  before  the  dam  failed, 
Luther  Wagoner,  C.E.,  who  was  employed  on  the  construction  of  the  dam 
part  of  the  time,  called  attention  to  "  some  very  bad  work  "  on  the  oater 


Fig.  33. — Cross-section  and  Elevation  op  Walnut  Grove  Dam,  Arizona. 


wall  near  the  mid-height,  and  states  that  he  *'  advised  the  company  to  cut 
a  large  wasteway  and  put  the  loose  rock  below  the  dam  to  strengthen  this 
weak  place."  The  following  is  extracted  from  Mr.  Wagoner's  paper:  The 
history  of  the  construction  of  the  dam  is  one  full  of  blunders,  mainly  caused 
by  the  officers  of  the  company  in  New  York.  Work  was  commenced  on 
company  account  by  Prof.  W.  P.  Blake,  who  carried  a  wall  across  the 


60 


RKSKRVOIliS  FOR  IRIilGATlOJV,   WATER-POWER,  ETC. 


canyon  to  bed-rock  tliroiigli  about  20  feet  of  sand  and  gravel.  He  was 
succeeded  by  Col.  E.  Ivobinson  as  chief  engineer,  and  the  work  was  con- 
tracted for  by  Nagle  &  Leonard  of  San  Francisco.  Under  Col.  Robinson 
the  dam  was  commenced  in  the  rear  of  the  Blake  wall,  and  was  described 
in  the  specifications  as  being  composed  of  front  and  back  walls  14  feet  at 
the  base  and  4  feet  at  the  top,  with  loose  rock-filling  between,  the  dam  to 
be  made  water-tight  by  a  wooden  skin  or  sheathing. 

"  Quarries  were  opened  by  the  contractors  upon  both  banks  of  the 
stream  above  the  top  of  dam.  '  Coyote  '  holes  from  8  to  15  feet  deep  were 
charged  with  low-grade  powder  (4^  nitro-glycerine),  and  the  stone  dislodged 
in  large  amounts.  The  stone  was  loaded  up  in  cars,  having  the  bed  inclined 
at  abont  15°,  and  these  were  lowered  onto  the  dam  by  a  bull-wheel  and 


Fig.  34.    View  of  Walnut  Grove  Dam,  Arizona, 


brake,  a  three-rail  railroad  being  laid  on  trestle  across  the  dam,  at  a  height 
of  from  10  to  15  feet.  On  the  slope  midway  was  a  turnout  so  as  to  allow 
the  loaded  cars  to  pass  the  empty  car.  The  loaded  car  was  unhooked  on 
the  level  and  ran  out  and  dumped  and  returned  above  by  the  next  loaded 
car.  The  legs  of  the  trestle  were  left  in  the  wall,  only  the  caps  and 
stringers  being  raised.  During  the  first  stages  of  construction  derricks 
were  used  to  distribute  the  larger  stones;  later  the  center  was  kept  high 
and  the  stones  from  the  wall  were  moved  by  bars.  The  effect  of  this  upon 
the  stability  of  the  dam  is  bad,  because  it  tends  to  form  curved  beds  whose 
slope  makes  an  acute  angle  with  the  direction  of  the  resultant  pressure. 


IWCK-FILL  DAMS. 


61 


"  The  company  purchased  a  sawmill  and  cut  the  Inmber  for  the  dams, 
buildings,  etc.,  and  the  skin  was  put  on  by  contract.  Cedar  logs,  8  to  10 
inches  in  diameter,  6  feet  long,  were  built  into  the  wall  on  the  upper  face, 
and  projected  out  one  foot.  Vertical  stringers,  6"  X  8",  of  native  pine^ 
were  bolted  to  the  logs;  the  stringers  were  about  4  feet  apart.  At  each 
joint  of  the  stringers  a  cedar  log  was  built  into  the  wall  about  2  inches 
above  the  joint,  and  two  4"  x  10"  spliced  pieces,  bolted  through  the  log 
and  spiked  to  the  6"  X  10"  pieces  with  galvanized-iron  boat-spikes,  com- 
pleted the  joint.  Upon  the  main  wall  of  the  dam  a  double  planking  of 
3-inch  boards  was  laid  horizontally,  having  a  tarred  paper  put  on  with 
tacks  between  the  planks.  The  outer  row  of  planks  was  calked  with 
oakum  and  painted  with  a  heavy  coat  of  paraffine  paint, — refined  asphaltum 
or  maltha,  dissolved  in  carbon  bisulphide.  The  junction  of  the  plank-skin 
and  the  bed-rock  was  secured  by  a  Portland  cement.  Through  the  dam  is 
a  wooden  culvert,  3x4  feet  inside,  about  the  level  of  the  old  creek 
channel;  this  is  boarded  with  3-inch  plank  inside  and  has  a  gate  to  draw 
oti  the  water  and  waste  it. 

*'  The  contract  for  the  dam  proper  was  for  46,000  cubic  yards,  lumped 
at  12.40  per  cubic  yard.  The  skin  and  cementing  was  extra.  Lumber  cost 
about  $15  per  M  at  the  dam. 

"  With  70  feet  of  water  above  bed-rock  the  dam  leaked  3.75  cubic  feet 
per  second.  Various  theories  were  advanced  for  the  cause  of  the  leak;  one 
was  that  settlement  of  the  dam  had  forced  an  opening  of  the  junction  of 
the  inclined  and  horizontal  skins;  and  another  was  that  it  leaked  over  the 
whole  surface.  The  extreme  right-hand  skin  below  the  bed  of  the  stream 
is  made  of  but  one  layer  of  plank.  The  machinery  for  draining  the  water 
was  inadequate,  and  the  men  who  did  the  cementing  assured  me  that  they 
worked  in  4  feet  of  water,  and  that  they  did  not  go  to  the  bed-rock.  The 
probable  cause  of  leakage,  I  believe,  is  due  to  all  three  of  the  reasons 
named." 

The  outlet  provided  for  the  reservoir  was  a  culvert  made  partly  in 
tunnels  through  a  spur  on  the  left  bank,  and  partly  as  an  arched  masonry 
conduit,  in  which  were  laid  two  20-inch  iron  pipes  with  gate-valves  at  the 
lower  end  below  the  dam.  These  pipes  terminated  above  the  dam  in  a 
square  wooden  tower  90  feet  high  built  of  8"  X  8"  timbers,  8  feet  long, 
notched  one-half  at  each  end,  secured  by  a  f-inch  rod  through  each  corner, 
the  joints  calked  with  oakum,  and  the  outside  painted  with  paraffine 
paint.  Two  wooden  valves  were  placed  to  admit  water  into  this  tower,  one 
at  the  bottom  and  the  other  20  feet  higher.  They  were  arranged  to  slide 
on  wood,  on  the  outside  of  the  tower,  with  wooden  valve-stems,  6  inches 
square,  running  up  the  outside  to  the  top,  where  the  operating  device  con- 
sisted of  two  pinions,  a  spur-wheel,  and  a  rack.  The  openings  were  each 
about  15  square  feet  in  area,  against  which  the  pressure  with  full  reservoir 


62 


JlESEIiVOJliS  FOR  IRIUOATION,   WArER-POWKR,  ETC. 


anion nted  to  a  resistance  or  load  of  nearly  40,000  lbs.  (estimating  the 
coefiicient  of  friction  of  wood  on  wood  at  0.40),  while  the  lifting-device 
gave  a  niaximnm  power  of  less  than  1000  lbs.  These  were  put  in  regardless 
of  the  protest  of  Mr.  Wagoner,  for  the  reason  assigned  that  "  they  were 
designed  by  an  engineer  and  must  work." 

This  defect  in  outlet,  however,  in  no  way  affected  the  stability  of  the 
dam,  and  even  had  it  been  possible  to  raise  the  gates  at  the  approach  of  the 
flood,  the  relief  which  they  would  have  afforded  could  not  have  averted  the 
disaster,  as  the  maximum  capacity  of  the  pipe  was  less  than  200  second- 
feet,  while  the  flood  must  have  been  several  thousand  second-feet  for 
a  considerable  period. 

SpilUvay.—ThQ  wasteway  as  built  was  26  feet  wide  and  7  feet  in  depth, 
constructed  at  the  right  bank  adjacent  to  the  dam,  the  spill  falling  near 
or  against  its  toe.  Its  maximum  capacity  when  full  was  1700  second- 
feet.  As  recommended  by  Mr.  Wagoner,  the  material  taken  from,  this 
spillway  was  placed  against  the  lower  side  of  the  dam,  as  a  loose  dump 
increasing  its  bottom  thickness  to  about  185  feet,  and  reaching  nearly  half- 
way up. 

Mr.  H.  M.  Wilson,  hydrographer,  U.  S.  Geological  Survey,  in  an  able 
review  of  the  construction  of  this  dam  published  in  1893,*  says: 
"  Mr.  Robinson  designed  a  wasteway  55  feet  wide  and  12  feet  deep,  cut 
through  a  ridge  one-half  mile  north  of  the  dam  and  spilling  into  a  separate 
watercourse,  which  would  in  all  probability  have  carried  off  the  great  flood 
of  1890.  For  some  unaccountable  reason  a  much  smaller  wasteway  was 
ultimately  constructed. " 

It  is  stated  that  the  spillway  was  being  enlarged  at  the  very  time  of  the 
destruction  of  the  dam.  Mr.  Wilson  further  says:  "  One  of  the  much-dis- 
cussed points  in  connection  with  the  construction  of  this  dam  was  its 
foundation;  it  was  intended  that  it  should  be  founded  on  bed-rock. 
Witnesses  before  the  courts,  men  who  had  taken  part  in  its  construction, 
claimed  that  the  foundation  did  not  reach  bed-rock  on  the  up-stream  face. 
The  body  of  the  loose  rock  rested  on  the  gravel  bed  of  the  river.  The 
lower  wall  rested  on  bed-rock,  but  a  portion  of  the  upper  wall  rested  only 
on  river  gravel.  This  fact  was  discovered  during  construction  of  the  dam. 
An  excavation  was  made  under  the  dam  and  a  masonry  wall,  14  feet  deep 
and  about  14  feet  wide,  was  laid,  presumably  to  bed-rock,  with  another 
portion  of  this  wall  turning  inward  to  the  east  on  bed-rock.  It  was 
claimed,  however,  that  this  wall  did  not  come  within  5  feet  of  bed-rock,  so 
that  in  fact,  even  after  the  alterations,  the  dam  still  rested  on  the  gravel. 
The  main  up-stream  wall  of  the  dam  rested  for  only  2|  feet  on  this 
secondary  base  which  was  built  under  it,  the  remainder  of  the  thickness  of 


"  American  Irrigation  Engineering,"  page  298. 


ROCK-FILL  DAMS. 


63 


the  wall  resting  on  the  buttress  which  inclined  inward  to  bed-rock.  The 
correctness  of  this  view  of  the  construction  of  the  dam  is  indicated  by  the 
fact  that  considerable  water  passed  under  or  through  the  dam  in  spite  of  its 
plank  sheathing." 

One  year  prior  to  the  bursting  of  the  dam,  Prof.  W.  P.  Blake  prepared 
a  paper  describing  it  which  was  published  in  the  Transactions  of  the 
American  Institute  of  Mining  Engineers,  New  York,  in  February,  1889, 
from  which  the  following  extract  is  taken: 

"  The  reservoir  was  filled  by  the  first  floods  and  the  water  rose  rapidly 
to  and  beyond  the  80-foot  contour-line.  As  to  the  effect  upon  the  stream 
below  there  has  been  an  agreeable  surprise  either  from  a  partial  opening  of 
one  of  the  gates  or  a  leak.  There  has  been  a  constant  flow  of  water  from 
the  dam,  and  this  has  kept  a  constant  stream  through  the  valley,  giving 
more  water  than  usual  along  its  course,  so  that  instead  of  the  owners  of 
water-privileges  denouncing  the  dam  and  asking  for  injunctions,  they  are 
hoping  the  dam  will  always  leak  to  their  advantage.  These  results  are  of 
great  value  as  to  the  demonstration  of  what  the  fuiictions  of  such  dams  and 
reservoirs  may  he  throughout  the  arid  regio7is  of  the  West;  even  if  not 
perfectly  tight,  they  would  be  of  immense  value  in  catching  the  temporary 
floods  and  in  equalizing  the  flow  of  such  intermittent  streams  as  the 
Hassayampa  and  many  others." 

It  is  remarkable  that  the  designer  of  this  dam  should  have  looked  upon 
the  really  enormous  leakage  developed  in  it  in  a  spirit  of  exultation,  as  an 
achievement  worthy  of  note,  rather  than  as  a  source  of  alarm  and  danger. 
To  write  of  such  leakage  as  one  of  the  results  "  of  great  value  "  requires 
unusual  confidence  in  the  stability  of  one's  work. 

None  of  the  published  descriptions  of  the  construction  of  the  dam  have 
stated  what  disposition  was  made  of  the  culvert  under  the  center  of  the 
dam  at  the  stream-bed,  after  construction  was  finished,  or  whether  it  was 
walled  up  or  merely  closed  by  a  wooden  gate. 

The  elevation  of  the  dam-site  is  about  3000  feet  above  sea-level,  while 
the  drainage-basin  of  311  square  miles  reaches  to  maximum  altitudes  of 
8000  feet.  The  mean  precipitation  of  the  shed  is  estimated  at  16  inches. 
The  capacity  of  the  reservoir  to  the  spillway-level,  83  feet  above  the  outlet 
tunnel,  was  about  10,000  acre-feet. 

The  water  was  intended  to  be  used  for  placer-mining  and  irrigation. 
A  diverting-dam,  located  some  20  miles  down  the  canyon,  was  in  process  of 
construction  at  the  time  of  the  final  catastrophe,  under  the  supervision  of 
Major  Alex.  0.  Brodie  (late  Major  of  First  Kegiment  U.  S.  Volunteer 
Cavalry),  who  barely  escaped  with  his  life. 

The  original  owners  of  the  property  have  had  in  contemplation  for  some 
time  past  the  reconstruction  of  the  dam  in  a  substantial  manner,  although 
plans  for  the  new  structure  have  not  been  made  public. 


64 


RESEIiVOJllS  FOR  JRRIGATION,  WATEIi-POWBJU,  ETC. 


East  Canyon  Creek  Dam,  Utah. — A  iiiodilicutioii  of  the  Otay  steel-core 
rock-fill  (lam  was  completed  April  1,  181)9,  on  East  Canyon  Creek,  Utah, 
forming  a  reservoir  of  5700  acre-feet  capacity,  to  he  used  for  irrigation, 
supplementary  to  the  supply  of  the  Davis  and  Weber  Counties  Canal 
Company. 

The  dam  is  G8  feet  high  above  the  creek-hed,  where  the  width  of  the 
canyon  is  but  50  feet.    The  length  of  the  dam  on  top  is  100  feet. 

A  concrete  wall,  15  feet  thick,  was  carried  down  through  the  gravel  bed 
of  the  car  yon  to  bed-rock,  a  depth  of  30  feet,  and  in  the  center  of  this  wall 
the  steel  web-plates  were  anchored.  These  are  -fj  inch  thick  for  the  lower 
20  feet,  I  inch  for  the  middle  20  feet,  and  inch  for  the  upper  28  feet. 
The  rock-fill  is  given  a  slope  of  |  to  1,  on  upper  side,  and  2  to  1  on  lower 
side,  the  top  width  being  15  feet.  In  construction  all  the  rock  necessary 
was  thrown  into  the  canyon  after  the  concrete  base  was  laid,  by  a  series  of 
heavy  blasts,  and  the  fill  consists  of  masses  that  in  some  cases  have  a  bulk 
of  100  cubic  yards.  The  canyon  walls  rose  to  a  height  of  more  than  100 
feet  above  the  top  of  the  dam  on  either  side,  and  the  material  in  falling 
packed  very  solidly  together.  After  the  rock-fill  was  thus  thrown  down  in 
sufficient  quantity  an  open  cut  was  excavated  in  it  down  to  the  concrete 
wall,  having  a  width  of  15  feet  at  base,  and  as  little  slope  on  sides  as  possi- 
ble. The  steel  core  was  then  erected  in  the  cat,  and  a  wall  of  stone  was 
laid  up  on  either  side,  leaving  a  space  of  4  inches  each  side  of  the  plate, 
which  was  filled  with  asphalt  concrete,  consisting  of  30^  sand,  70fo  gravel, 
and  sufficient  asphalt  to  fill  the  voids,  requiring  8  lbs.  per  cubic  foot  of  the 
mass.  The  inner  portion  of  the  rock-fill  was  laid  up  as  a  substantial  dry 
wall  with  headers  and  stretchers,  reaching  from  the  plate  out  to  the  water- 
face,  the  main  rocks  being  placed  with  a  derrick.  Notwithstanding  the  care 
given  in  this  construction  the  settlement  of  the  wall  as  the  water  rose  upon 
it  to  a  height  of  45  feet  was  so  great  as  to  draw  the  asphalt  concrete  away 
from  the  plate,  an  extreme  distance  of  5  feet  at  the  top,  bending  towards 
the  lake,  and  forming  a  curve  from  a  point  about  30  feet  below  the  top, 
and  finally  the  upper  portion  of  the  wall  fell  off,  as  indicated  by  the  broken 
line  in  Fig.  35.  The  down-stream  portion  also  settled  somewhat,  causing 
the  concrete  to  part  from  the  steel  plates  about  6  inches  at  the  top. 

This  peculiar  action  is  thought  to  have  been  caused  by  the  adhesion  of 
the  asphalt  to  the  stone  wall,  the  bond  being  stronger  with  the  stone  than 
its  adhesion  to  the  steel  plates.  The  rock  used  is  a  conglomerate  with  an 
admixture  of  red  clay,  which  disintegrated  when  wet  and  produced  the 
extreme  settlement. 

The  dam  remained  with  full  head  of  water  against  it  for  several  months 
without  apparent  leakage,  except  through  crevices  in  the  bed-rock,  and  it 
is  believed  the  expense  of  repairs  will  be  light.  The  total  cost  of  the 
structure  was  140,000. 


ROCK  FILL  DAMS. 


65 


66  ItESERVOIUS  FOR  IRRIUATION,  WATER-POWER,  ETC. 


The  outlet  to  the  reservoir  is  by  means  of  a  tunnel  200  feet  long,  the 
bottom  of  which  is  10  feet  above  the  original  stream-bed.  At  the  entrance 
to  the  tunnel  two  30-incli  riveted  steel  pipes  f  inch  thick  are  imbedded  in 
concrete,  controlled  by  30-inch  Ludlow  valves  bolted  to  them,  operated 
from  a  platform  projecting  from  the  face  of  the  cliff  above.  The  valve- 
stems  are  2^-inch  steel  pipes.  The  main  control  of  the  outlet  is  by  means 
of  two  other  valves  of  the  same  size,  placed  at  the  bottom  of  a  shaft,  50  feet 
back  from  the  mouth  of  the  tunnel,  between  two  lengths  of  cast-iron  pipe, 
the  whole  being  imbedded  in  concrete  which  completely  fills  the  tunnel. 
These  are  the  working  valves,  the  others  being  used  only  in  emergency. 

The  spillway  is  at  one  end  of  the  dam,  and  consists  of  a  flume  6  feet 
deep,  27  feet  wide,  discharging  below  the  toe  of  the  dam.  The  available 
depth  of  the  reservoir  between  the  bottom  of  the  spillway  and  the  floor  of 
the  tunnel  is  52  feet. 

Mr.  W.  M.  Bostaph  was  the  engineer  in  charge,  and  Mr.  Samuel  Fortier 
was  consulting  engineer. 

This  account  of  the  construction  is  an  abstract  of  an  article  in  Engineer- 
ing Record,  by  M.  S.  Parker,  M.  Am.  Soc.  C.  E.  The  writer  is  indebted 
to  the  Record  for  the  loan  of  the  cut  illustrating  the  construction. 

Theoretically  the  plan  of  imbedding  the  steel  core  in  the  center  of  a 
wall  of  asphalt  concrete  was  an  improvement  npon  that  of  the  Otay  dam, 
and  had  there  been  no  settlement  of  the  rock  the  construction  would  have 
been  faultless.  But  in  the  Ofcay  dam  the  steel  core  and  the  cement  concrete 
either  side  of  it  are  independent  of  the  rock-fill,  which  is  free  to  settle 
without  pulling  on  the  core.  This  is  undoubtedly  a  superior  plan,  although 
the  ultimate  action  of  settlement  when  the  reservoir  is  filled  remains  to  be 
tested  in  the  Otay  dam,  as  up  to  the  present  writing  it  has  never  been  filled. 
It  has  been  feared  that  a  rupture  of  the  plates  might  be  produced  by  the 
strains  of  unequal  settlement. 

Denver  Water  Company's  Rock-fill  Dam. — The  third  American  dam 
where  steel  plates  are  employed  to  give  water-tightness  to  a  rock-fill  is  in 
process  of  erection  on  the  South  Fork  of  the  South  Platte  Kiver,  48  miles 
above  Denver,  Colorado,  by  the  Denver  Union  Water  Company.  It  is  the 
highest  and  most  pretentious  dam  of  its  class  that  has  ever  been  projected, 
and  when  completed  it  will  be  one  of  the  highest  dams  in  the  world.  Its 
estimated  cost  is  $350,000.  It  is  to  be  210  feet  high,  600  feet  long  at  top, 
and  have  a  base  of  450  feet,  up  and  down  the  canyon.  The  dam  is  being 
constructed  as  a  rock-fill,  loosely  dumped  from  cars  that  run  by  gravity 
from  the  quarries  out  upon  a  bridge  that  spans  the  canyon  above  the  top  of 
the  dam.  The  lower  slope  is  li  to  1,  and  the  upper  slope  i  to  1,  with  a 
dry,  hand-laid  wall,  15  feet  thick  at  bottom,  5  feet  in  thickness  at  top,  on 
the  water-face.  Over  the  face  of  this  wall  on  the  slope  is  placed  a  web  or 
skin  of  sheet-steel  plates,  1130  in  number,  dipped  in  asphalt,  and  riveted 


BOCK-FILL  DAMS. 


67 


to  6-inch  T  beams,  placed  5  feet  apart,  and  resting  against  the  wall.  The 
plates  are  flanged  at  the  side  of  the  canyon  and  bolted  to  the  solid  granite, 
with  split  bolts,  driven  1  foot  deep  into  the  rock.  The  space  between  the 
plates  and  the  face  of  the  dry  wall  is  filled  with  concrete,  and  the  entire 
sheet  is  covered  with  a  layer  of  concrete  from  the  bottom  up  to  a  height  of 
126  feet,  or  10  feet  above  the  top  of  the  upper  outlet  or  spillway  tannel. 
The  plates  are  5'  X  10'  X  f"  thick  for  75  feet  in  height;  then  for  the 
second  75  feet  the  thickness  is  reduced  to  -^-^  inch,  and  for  the  remaining 
60  feet  to  ^  inch  in  thickness,  the  size  being  uniform  throughout.  For  the 
upper  80  feet  the  plates  will  be  unprotected  from  the  action  of  the  elements, 
except  by  such  paint  as  may  be  applied  from  time  to  time.  The  spillway 
tunnel  being  located  below  this  level  permits  the  inspection  of  the  exposed 
plates  at  any  time  by  drawing  down  the  water  of  the  reservoir.  The  gorge 
is  an  exceptionally  narrow  one,  and  the  walls  are  of  remarkably  hard 
granite,  of  close  texture,  and  comparatively  free  from  seams  or  fissures. 
Indeed  the  site  would  be  regarded  as  a  particularly  favorable  one  for  a 
masonry  dam,  although  its  remoteness  in  the  mountain  fastnesses  would 
render  the  cost  of  cement  for  masonry  very  high.  At  the  extreme  base, 
which  is  18  feet  below  the  outlet  tunnel,  the  width  between  canyon  walls  is 
but  43  feet.  The  volume  of  rock  required  for  the  structure  is  estimated  at 
225,000  cubic  yards,  which  is  very  small  indeed  for  an  embankment  of  such 
unusual  height. 

Outlet. — The  main  reservoir  outlet  is  a  tunnel  starting  100  feet  above 
the  dam  at  the  base,  and  piercing  the  spur  of  the  mountain,  forming  one 
of  the  abutments  of  the  dam.  This  tunnel  is  7  feet  wide,  and  6  feet  high 
for  about  half  its  length,  to  the  junction  with  the  inclined  spillway  tunnel, 
whence  its  size  is  increased  to  8  feet  wide  and  9  feet  high,  the  total  length 
being  470  feet. 

The  spillway  tunnel  starts  110  feet  above  the  lower  tunnel  and  dips  at 
an  incline  of  45°  to  its  intersection  with  the  lower  tunnel.  Its  size  is 
7x6  feet.  Both  tunnels  are  controlled  at  the  upper  end  by  balanced 
valves,  set  over  the  tunnel-mouth  at  an  incline  of  30"  from  the  horizontal. 
These  valves  are  closed  by  gravity,  and  opened  by  hydraulic  pressure  con- 
veyed to  the  cylinders  at  one  end  of  the  valves  through  lead-lined  steel 
pipes,  laid  in  trenches  surrounded  by  concrete,  from  the  valves  to  a  reservoir 
located  at  suitable  height  on  the  adjacent  mountainside.  When  submerged 
there  will  be  no  other  connection  with  the  surface,  and  no  other  means  of 
moving  the  valves.  The  opening  of  a  faucet  will  put  on  the  pressure  that 
will  open  the  valves  and  release  the  water  from  the  reservoir,  and  the  entire 
operation  will  be  out  of  sight  and  perfectly  noiseless.  The  valve  was  made 
from  drawings  prepared  by  the  chief  engineer,  Mr.  Charles  P.  Allen,  to 
whose  courtesy  the  writer  is  indebted  for  the  accompanying  illustrations. 
Fig.  36  illustrates  the  construction  of  the  valve,  which  consists  of  four 


68 


RESEUV0IR8  FOR  IRRIGATION;  WATER-POWER,  ETO, 


hoods,  or  chambers,  of  cast  iron,  resting  on  a  heavy  framework  of  T  beams 
and  opening  out  into  the  tunnel  at  the  bottom.  A  continuous  shaft  passes 
through  all  the  hoods  from  end  to  end,  upon  which  are  fastened  heavy  disks 
of  cast  iron,  so  spaced  as  to  close  all  the  openings  in  the  hoods  when  the 
valve  is  shut,  and  uncover  openings  at  each  end  of  each  hood  when  the 
shaft  is  moved.  The  hydraulic  cylinder,  in  which  power  by  water  under 
pressure  is  applied,  is  shown  at  one  end  of  the  valve,  which  end  is  highest 
as  the  valve  lies  inclined  over  the  tunnel-mouth.  The  valve  weighs  about 
eight  tons  and  cost  $1800  at  the  shops  in  Denver. 

Additional  control  of  the  reservoir  outlet  is  afforded  by  two  42-inch 
gate- calves,  imbedded  in  concrete  in  the  tunnel  a  short  distance  above  the 


Fig.  36. — Balanced  Valve,  used  for  Reservoir  Outlet,  Sooth  Platte  Kock 

FILL  Dam,  Colo. 


point  of  junction  with  the  spillway  tunnel.  These  lie  on  their  edges,  side 
by  side,  with  their  stems  pointing  away  from  the  tunnel  and  attached  to 
hydraulic  cylinders,  which  afford  the  power  for  actuating  the  valves.  To 
make  room  for  this  mechanism  a  chamber  was  excavated  in  the  rock  on  each 
side  of  the  tunnel,  17.5  feet  deep,  12  feet  wide,  and  7  feet  high.  The 
gates  are  placed  in  the  line  of  the  upper  sides  of  these  chambers,  heavily 
anchored  to  the  bed-rock  by  steel  straps  and  anchor-bolts  on  all  sides,  with 
vertical  T  beams  placed  against  the  lower  side  of  the  gate-frames,  and  the 
whole  imbedded  in  concrete,  so  placed  as  to  form  a  smooth  funnel  leading 
to  the  gates  from  above,  and  spreading  out  to  the  size  of  the  tunnel  below. 

Beneath  the  gates  are  two  12-inch  pipes  controlled  by  gate-valves,  to 
serve  as  a  by-pass.  The  necessity  for  heavy  construction  at  this  point  is 
appreciated  when  it  is  considered  that  the  pressure  upon  this  bulkhead 
when  the  reservoir  is  full  is  nearly  600,000  lbs.    The  hydraulic  cylinders 


Fig.  37.— South  Platte  Rock-fill  Dam.   View  op  False  Work  and  Bridge  oyer 

THE  Dam-site. 

The  stone  for  the  rock-filling  is  dumped  from  the  top  of  Ibis  bridge  to  the  canyon 

below. 

69 


BOCK-FILL  DAMS. 


71 


and  all  the  moving  parts  of  the  valves  are  accessible  from  the  chambers  in 
"which  they  are  placed,  and  from  which  the  water  is  excladed  by  concrete 
walls  separating  the  chamber  from  the  tunnel  proper. 

The  reservoir,  when  full,  will  cover  775  acres  and  extend  up  the  canyon 
a  distance  of  7  miles.  Its  maximum  capacity  will  be  67,210  acre-feet,  or 
21,900,000,000  gallons.  A  table  of  contents  and  areas  at  different  levels 
will  be  found  in  the  Appendix. 

This  site  was  examined,  surveyed,  and  reported  upon  favorably  in  1897 
by  Col.  H.  M.  Chittenden,  Corps  of  Engineers,  U.  S.  A.,  under  authority 
of  the  Congressional  Eiver  and  Harbor  Act  of  June  3,  1896,  directing  an 
examination  of  at  least  one  site  each  in  the  States  of  Wyoming  and 
Colorado  "for  the  storage  and  utilization  of  water,  to  prevent  floods  and 
overflows,  erosion  of  river  banks  and  breaks  of  levees,  and  to  reinforce  the 
flow  of  streams  during  drought  and  low- water  seasons." 

In  his  able  and  exhaustive  report  on  this  subject  Col.  Chittenden  says: 

"  This  site  is  remarkable  in  affording  an  excellent  place  for  a  high 
masonry  dam."  He  recommends  a  dam  200  feet  high,  on  curved  plan, 
with  300  feet  radius,  whose  cubical  contents  would  be  75,200  cubic  yards. 
His  estimate  of  cost  was  $540,000.  The  area  of  watershed  above  the  dam 
is  given  at  1645.2  square  miles,  and  the  volume  which  could  probably  be 
stored  annually  at  43,620  acre-feet,  or  a  mean  of  60  second-feet.  The 
average  run-off  for  1896,  a  low  year,  was  estimated  to  be  about  166  second- 
feet  past  the  dam-site.  The  loss  by  evaporation  he  estimates  at  not  exceed- 
ing 100,000,000  cubic  feet  annually. 

The  dam  was  expected  to  reach  the  height  of  100  feet  by  May,  1900. 
Fig.  37  shows  the  false  work  for  the  erection  of  the  bridge  across  the 
canyon,  from  which  the  rock  is  dumped.  This  bridge  rests  on  trestle 
piers  at  the  ends,  which  are  long  enough  to  permit  the  bridge  to  be  moved 
up  and  down  stream  to  facilitate  the  spreading  of  the  rock-fill  uniformly 
over  its  base.    The  outlines  of  the  reservoir  are  shown  on  Fig.  38. 

The  English  Dam,  California. — Among  the  earlier  constructions  of  the 
rock-fill  type  was  one  known  as  the  English  dam,  situated  on  the  headwaters 
of  the  Middle  Fork  of  the  Yuba  Eiver,  in  California,  at  an  elevation  of 
6140  feet,  which  was  destroyed  June  17,  1883.  The  reservoir  was  formed 
by  means  of  three  timber  crib-dams,  and  covered  an  area  of  395  acres, 
impounding  650,000,000  feet  of  water.  It  was  supplied  by  the  run-off  from 
a  drainage  area  of  12.1  square  miles,  reaching  to  the  summit  of  the  Sierra 
Nevada.  The  middle  dam,  the  largest  of  the  three  and  the  one  which  was 
subsequently  destroyed,  had  a  vertical  height  of  100  feet  on  the  interior, 
and  131  feet  on  the  exterior,  above  the  deepest  part  of  the  foundation.  Its 
thickness  at  base  was  185  feet,  length  on  top  331  feet,  and  bottom  length 
about  50  feet.  The  original  construction  consisted  of  a  crib  made  of  tama- 
rack logs,  79  feet  high,  100  feet  thick  at  base,  with  inner  slope  of  60°  from 


JtEJSEIiVOJ/lS  FOR  JIlIiTGATION,  WATER- POWER,  ETC. 


ROCK-FILL  DAMS. 


73 


the  horizontal,  the  crib  being  filled  with  rock,  and  the  whole  stracture 
faced  with  plank.  It  was  built  in  1856,  and  repaired  in  1876-77,  by  tear- 
ing out  the  decayed  portion  of  the  old  crib  and  replacing  it  with  new 
timbers.  At  the  same  time  an  addition  to  the  thickness  and  height  was 
made  by  building  a  stone  facing  on  the  outside,  laid  up  as  a  dry  rubble 
wall,  on  a  slope  of  44°.  This  wall  was  carried  up  to  a  height  of  14  feet 
above  the  top  of  the  original  dam,  meeting  a  similar  wall  laid  on  the  inner 
slope.  The  upper  7  feet  was  formed  of  a  substantial  timber  cribwork. 
The  addition  to  the  dam  cost  170,000,  and  the  entire  cost  of  the  three  struc- 
tures was  $155,000,  or  110.40  per  acre-foot  of  storage  capacity.  The 
high-water  mark,  or  the  spillway-level,  was  14  inches  below  the  top  of  the 
upper  cribwork.  From  the  time  the  repairs  were  completed  until  the 
destruction  of  the  dam,  about  five  years,  no  signs  of  weakness  or  leakage 
were  manifest,  and  the  water-level  was  raised  annually  to  the  high-water 
mark.  On  the  evening  before  the  break  the  water-level  was  2^  inches  below 
the  spillway.  The  first  intimation  given  of  the  break  was  at  5.30  a.m., 
when  the  watchman  heard  two  violent  explosions,  and  on  reaching  a  point 
where  he  could  see  the  dam  he  observed  the  water  pouring  through  a  wide 
breach  in  the  upper  cribwork.  It  was  inferred  that  the  break  had  been 
caused  by  dynamite.  In  a  few  moments  the  water  cut  an  immense  gap 
through  the  structure  to  its  very  foundation  and  the  entire  contents  of  the 
reservoir  were  emptied  inside  of  an  hour.  The  flood-wave  caused  a  rise  of 
40  feet  at  a  point  43  miles  below.  At  Marysville,  85  miles  below,  the  rise 
observed  was  but  2  feet  8  inches,  and  at  Sacramento  the  extreme  rise  was 
but  8  inches.  The  damage  done  by  the  flood  was  estimated  at  about  $4000 
to  some-  wheat-fields  that  were  overflowed.  The  flood  was  24  hours  in 
reaching  Sacramento,  and  the  total  time  in  passing  that  point  was  26  hours. 
Had  the  break  occurred  in  time  of  flood  the  opinion  is  expressed  by  A.  J. 
Bowie,  M.E.,  that  it  would  not  have  been  observed  by  a  marked  increase 
in  the  level  of  the  larger  streams  of  the  Sacramento  Valley— the  Feather 
and  Sacramento  rivers.*  While  the  composite  character  of  this  structure, 
and  its  age  at  the  time  of  its  failure,  would  lessen  confidence  in  its  stability, 
it  is  the  only  one  of  its  type  which  has  given  way,  and  the  circumstances 
seem  to  point  to  malice  rather  than  inherent  weakness  as  the  possible  cause 
of  its  failure. 

The  volume  of  water  released  by  the  breaking  of  the  dam  was  about 
600,000,000  cubic  feet,  which  exceeded  by  nearly  20^  the  contents  of  the 
8outh  Fork  reservoir  whose  failure  produced  the  frightful  Johnstown, 
Penn.,  disaster  in  1889,  and  that  there  was  no  loss  of  life  resulting  from  it 
and  very  slight  property  damage  is  quite  remarkable. 


*  Transactions  Technical  Society  of  the  Pacific  Coast,  vol.  ii.  page  10,— A  Paper 
on  the  Destruction  of  the  English  Dam. 


74  liESEUVOniS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


The  Bowman  Dam. — The  timber-crib  rock-filled  dams  of  the  mining 
ref^ions  of  California  are  well  illustrated  by  the  Bowman  dam,  located  on 
the  Sonth  Fork  of  Yuba  Kiver,  and  impounding  the  drainage  from  19 
square  miles  of  the  higher  Sierras. 

The  dam  was  built  in  1872  to  the  height  of  72  feet  in  a  manner  similar 
to  the  original  construction  of  the  English  dam,  consisting  of  a  timber  crib 
of  unhewn  cedar  and  tamarack  logs,  notched  and  bolted  together  and  filled 
with  small  stones.  The  slopes  on  each  side  were  1  on  1,  and  the  face  was 
made  with  a  skin  of  pine  planking,  laid  horizontally.  In  1875  the  dam  was 
raised  to  the  extreme  height  of  100  feet,  by  adding  an  embankment  of  stone 
to  the  lower  slope,  wide  enough  to  carry  the  entire  structure,  including  the 
crib-dam,  to  the  desired  height.  The  outer  face  of  this  embankment  was 
made  as  a  hand -laid  dry  rubble  wall  in  which  stone  of  large  size  were  used. 
This  wall  is  15  to  18  feet  thick  at  base,  and  6  to  8  feet  at  the  top,  the  stone 
weighing  from  |  ton  to  4|  tons.  Vertical  ribs  were  bolted  to  the  wall  on 
the  water-face,  with  f-inch  rods,  5  feet  long,  and  to  these  the  plank  were 
spiked.  These  were  9  inches  thick,  in  three  layers,  for  the  bottom  25  feet, 
6  inches  thick  for  the  next  35  feet  in  height,  and  3  inches  thick  on  the 
upper  36  feet.  The  outlet  to  the  reservoir  is  arranged  by  three  18-inch 
wrought-iron  riveted  pipes,  about  25  feet  long  each,  extending  from  the 
inner  face  of  the  dam  to  a  culvert,  built  in  the  dam  from  the  lower  side  to 
the  gates  placed  at  the  outlet  end  of  these  pipes.  The  combined  discharg- 
ing capacity  of  the  pipes  is  280  second-feet,  when  the  reservoir  is  fall. 
They  discharge  into  a  covered  sluice  or  flume  in  the  bottom  of  the  culvert, 
21  inches  high,  7|  feet  wide.  The  gates  are  approached  by  a  walk  above 
this  flume.  The  culvert  is  8  feet  high,  7.5  feet  wide  at  bottom,  b\  feet  at 
top,  made  of  dry  rubble  side  walls,  covered  with  heavy  granite  slabs, 
18  inches  thick,  6.5  feet  long. 

The  dam  is  425  feet  long  on  top,  and  has  a  base  thickness  of  180  feet. 
Its  contents  are  55,000  cubic  yards,  and  its  cost  was  $151,521.44. 

Like  many  of  the  earlier  types  of  rock-fill  dams  it  was  built  with  an 
obtuse  angle  in  the  center,  whose  apex  is  pointed  up-stream.  This  angle  is. 
165°.  Its  purpose  was  evidently  to  give  a  fancied  additional  security,  and 
was  the  nearest  approach  to  the  arched  form  which  could  conveniently  be 
given  to  such  a  structure. 

The  reservoir  covers  an  area  of  nearly  500  acres,  when  full,  and  has  a 
maximum  capacity  of  918,000,000  cubic  feet  or  21,070  acre-feet.  Its  cost 
was  therefore  an  average  of  $7.19  per  acre-foot  of  storage  capacity. 

The  annual  precipitation  at  the  Bowman  dam,  as  recorded  for  sixteen 
years  prior  to  1887,  ranged  from  a  minimum  of  44  inches  to  a  maximum  of 
120  inches,  the  mean  being  about  72  inches.  The  watershed  is  of  a 
character  to  yield  maximum  run-off  estimated  at  75^  of  mean  precipitation. 
Maximum  floods  from  melting  snows  reach  5000  to  7000  cubic  feet  per 


PLAN 


C/fOSS  SECTfo/v 

Fig.  38a  —Plan  and  Cross-section  of  the  Bowman  Dam,  an  Eauly  Type  op 
THE  California  Rock-fill  Dam  fok  Hydraulic  Mining  Storage. 


[To  face  page  74. 


BOCK-FILL  DAMS. 


75 


second.  The  minimnm  annual  rainfall  is  safficienfc  to  give  ample  rnn-ofL 
to  fill  the  reservoir,  while  the  maximum  precipitation  would  yield  sufficient 
to  fill  it  four  times  in  one  year.  The  crest  of  the  spillway  is  placed  but  18 
-nches  below  the  crest  of  the  dam.  The  latter  is  made  as  a  coping  of  hewn 
cedar,  18  inches  wide  on  top,  anchored  by  iron  bolts  into  the  wall.  The 
structure  is  so  well  built  that  a  few  inches  depth  of  water  overflowing  the 
crest  of  the  dam  would  pass  off  without  injury  to  the  lower  slope-wall. 
The  reservoir  is  owned  by  the  North  Bloomfield  Mining  Company,  and  the 
water  is  used  for  hydraulic  mining. 

The  same  company  have  four  smaller  reservoirs  of  similar  type,  con- 
structed at  a  total  cost  of  $95,000.  The  following  table  gives  the  capacity 
of  the  principal  mining-reservoirs  of  California,  which  have  been  the  proto- 
types of  rock-fill  dam  construction  in  the  West,  some  of  which  have  been 
more  fully  described  in  the  foregoing  pages.  Many  of  them  are  located  at 
the  sites  of  natural  lakes  whose  surfaces  have  been  raisri  by  the  erection 
of  dams  at  their  outlets. 


Capacity  of  the  Principal  MiNiNG-RESEHvoms  of  the  Hydraulic  Mining 
Districts  of  Northern  California. 


Name. 


Bowman , 


Sliotgun  Lake 
Inland  Lake. . 
Middle  Lake. . 
Round  Lake.. . 
Weaver  Lake. 


Eureka  Lake.  .  . 
FaucLerie  Lake 
Jackson  Lake . . . 
Smaller  lakes.. . 
English  dam. .  . 
Fordyce  dam. . . 


Meadow  Lake. 
Sterling  Lake. 

Omega  

California  , .  .  . 


Company. 


Nortli  Bloomfield 
Mining  Co. 
Do. 
Do. 
Do. 
Do. 

Eureka  Lake  Min- 
ing Co. 
Do. 
Do. 
Do. 
Do. 

Milton  Mining  Co. 
South  Yuba  Min- 
ing Co. 

Do. 

Do. 


Capacity  of 
Reservoir. 


Cubic  Feet. 

900,000,000 
3,433,000 
23,028,000 
2,395,800 
2,907,700 

150,000,000 
661,000  000 
58,800,000 
15,000,000 
50,000,000 
650,000,000 

1,075,525,000 
107,950,000 
53,975,000 
300,000,000 

1,071,000,000 


Area. 


500.0 
26.2 
48  8 


10.3 

83.5 
337.3 
90.0 
20.0 


395.0 

1,200.0 
262.0 


Height  of 
Dam. 


Feet. 

100.0 
10.0 
12.8 


3.0 

21.8 
68.2 
21.0 
5.0 


131  0 

75.0 
28.0 
30.0 


Length  of 
Dam. 


Feet. 

425 


250 
331' 


650 
500 
300 


CHAPTER  II. 


HYDRAULIC-FILL  DAM-CONSTRUCTION. 

The  forces  employed  in  hydraulic  mining  for  tearing  down  a  bank  of 
sand,  by  the  use  of  a  large  volnme  of  water  issuing  from  a  nozzle  under 
pressure,  gravel,  and  rock,  ^nd  transporting  the  materials  considerable  dis- 
tances on  suitable  grades  while  suspended  in  water  and  depositing  them 
where  desired,  have  been  utilized  in  the  evolution  of  a  novel  and  interesting 
type  of  dam-construction,  which  in  many  localities  can  be  applied  success- 
fully where  the  cost  by  other  methods  would  be  prohibitive.  The  condi- 
tions required  for  the  successful  employment  of  hydraulic-dam  construction 
are: 

1st.  The  existence  of  an  abundance  of  water  at  the  proper  elevation  to 
form  a  sufficient  "  sluicing-head  " ; 

2d.  An  abundant  deposit  of  materials  for  forming  the  dam,  convenient 
to  either  end,  and  high  enough  above  the  top  of  the  proposed  structure  to 
permit  of  the  requisite  grades  for  carrying  the  material;  and 

3d.  A  suitable  foundation,  which  is,  of  course,  requisite  in  all  dams. 

The  volume  of  water  necessary  for  a  "  sluicing-head"  should  be  from 
5  to  10  cubic  feet  per  second,  although  smaller  heads  may  be  used.  Ten 
second-feet  may  be  readily  handled  in  one  head,  and  is  more  effective  pro- 
portionally than  smaller  heads.  The  duty  of  water  in  hydraulic  mining  in 
California  per  miner's  inch  per  24  hours  ranges  from  2  to  5  cubic  yards 
of  solid  bank  measure  loosened  and  washed  down.  This  is  equivalent  to  a 
duty  of  from  80  to  200  cubic  yards  removed  in  24  hours  per  second-foot  of 
water.  The  ratio  of  water  to  solids  would  thus  be  from  2.5^  to  6.25^.  In 
hydraulic  gold-mining  it  is  essential  to  keep  the  percentage  of  solids  quite 
low  to  permit  the  gold  to  drop  freely  to  the  bottom  of  the  sluice-boxes, 
where  it  is  caught  by  quicksilver.  In  dam-construction,  on  the  contrary, 
it  is  desirable  to  maintain  as  high  a  percentage  of  solids  as  the  water  will 
transport.  With  sluice  grades  of  6^  to  10^,  the  volume  which  may  be 
transported  by  a  sluicing-head  of  10  second-feet  is  2000  to  4000  cubic  yards 
per  24  hours. 

The  most  suitable  material  is  an  admixture  of  soil,  sand,  and  gravel  of 
all  sizes.    Small  angular  stones,  not  exceeding  100  lbs.  weight,  may  be 

76 


HYDRA  ULIC-FILL  DAM  C0N8TB  UCTION. 


77 


carried  through  the  sluice-boxes  with  a  snfficient  amount  of  sand  and  soil 
to  enable  it  to  flow  well.  It  is  customary  to  deposit  the  materials  on  the 
dam  on  the  lines  of  the  two  slopes,  which  are  studiously  kept  higher  than 
the  center  of  the  embankment.  The  larger  stones  are  here  dropped,  while 
the  finer  materials  are  carried  towards  the  center  where  the  water  is  drawn 
off  through  stand-pipes  which  lead  back  into  the  reservoir  or  which  conduct 
it  to  a  flume  or  pipe  by  which  it  may  be  wasted  below  the  dam. 

The  material  for  this  class  of  construction  may  either  be  loosened  by  a 
hydraulic  jet  of  water  issuing  under  pressure  and  playing  against  the  bank, 
which  is  the  cheaper  and  more  rapid  method,  or  if  pressure  is  not  available 
it  may  be  plowed  or  picked  and  ground-sluiced. 

San  Leandro  and  Temescal  Hydraulic-fill  Dams,  California. — This  pro- 
cess of  building  up  reservoir-embankments  has  been  in  vogue  in  a  small  way 
in  the  mines  of  California  from  the  earliest  days  of  hydraulic  mining,  but 
the  first  application  of  it  on  a  large  scale  was  made  by  Mr.  A.  Chabot,  in 
the  construction  of  the  reservoir-dams  for  the  water-supply  of  Oakland, 
California,  a  city  of  60,000  inhabitants. 

These  dams  were  planned  and  built  by  Mr.  A.  Chabot,  who,  though  not 
an  engineer,  had  had  years  of  experience  as  a  practical  hydraulic  miner  and 
was  the  principal  owner  of  the  water-works.  They  are  both  earthen  dams, 
of  which  the  central  portion,  including  the  puddle-core,  were  built  up  with 
scraper  teams  and  rollers  in  the  ordinary  way,  but  extensive  additions  to 
their  slopes  and  height  were  made  by  hydraulic  sluicing. 

The  Temescal  dam  was  built  in  1868.  It  is  105  feet  high,  18  feet  wide 
on  top,  with  original  slopes  of  2^  to  1,  which  have  been  greatly  increased 
by  the  material  sluiced  in  from  year  to  year  subsequently.  The  w^ater 
available  being  limited  in  supply  to  a  few  days  each  season  after  storms,  the 
work  was  continued  for  a  number  of  seasons  as  an  economical  method  of 
increasing  the  bulk  of  the  dam.  It  forms  a  reservoir  of  18.5  acres,  with  a 
capacity  of  188,000,000  gallons. 

The  San  Leandro  dam  was  built  in  1874-75,  and  has  a  height  of  120 
feet  above  the  stream-bed.  It  is  located  9.5  miles  east  from  Oakland,  1.5 
miles  above  the  village  of  San  Leandro,  at  an  elevation  at  base  of  115  feet 
above  tide.  The  total  volume  of  the  dam  is  542,700  cubic  yards,  of  which 
about  160,000  yards  were  deposited  by  the  hydraulic  process.  The  water 
was  brought  4  miles  in  a  ditch,  and  the  sluiced  materials  were  conveyed  in 
a  flume,  lined  with  sheet-iron  plates  and  laid  on  a  grade  of  4^  to  6^.  The 
water  used  was  10  to  15  second-feet,  and  the  ground-sluicing  method  was 
alone  employed,  as  it  was  not  convenient  to  get  water  under  pressure.  The 
cost  was  estimated  at  one-fourth  to  one-fifth  that  of  putting  the  earth  in 
place  with  carts  or  scrapers.  The  entire  cost  of  the  dam  proper  was  about 
$525,000,  but  the  outlets,  wasteway-tunnels,  and  improvements  of  various 
kinds  about  the  reservoir  have  increased  the  total  to  over  1900,000,  or  about 


78 


JiESEnvorns  for  ihuigation,  water-poweh,  etc. 


$08  per  acre-foot  of  storage  capacity.  The  reservoir  covers  an  area  of  335 
acres  and  has  a  maximum  capacity  of  13,270  acre-feet,  or  4,323,446,000 
gallons.  The  area  of  the  watershed  tributary  to  the  San  Leandro  dam  is 
50  square  miles,  from  which  the  run-off  is  ordinarily  in  excess  of  the  storage 
capacity,  and  considerable  difficulty  was  experienced  in  disposing  of  the 
surplus,  without  washing  away  the  dam,  until  a  waste-tunnel,  1100  feet 
long,  with  a  capacity  of  2000  second-feet,  was  constructed  in  1888,  discharg- 
ing into  the  stream  half  a  mile  below  the  dam. 

The  plans  and  sections  of  these  dams  are  shown  in  Fig.  39,  in  which  are 


Fig.  39.— Plans  and  Ceoss-sections  of  San  Leandro  and  Temescal  Dams. 


represented  the  restraining  levees  for  holding  the  sluiced  material  in 
terraces,  as  it  was  deposited  on  the  outer  slopes.  The  deposit  on  the  inside 
was  made  by  simply  dumping  the  contents  of  the  flume  into  the  water  and 
allowing  it  to  assume  its  own  slope  on  the  surface  of  the  embankment. 

Hydraulic-fill  Dam  at  Tyler,  Texas. — In  projecting  improvements  to  the 
water-works  of  Tyler,  Smith  County,  Texas,  in  May,  1894,  the  engineer  of 
the  company,  J.  M.  Howells,  Q.E,,  conceived  the  idea  of  creating  an 
impounding-reservoir  by  means  of  a  dam  to  be  constructed  by  the  hydraulic- 
jet  and  sluicing  method.  The  only  means  of  getting  water  to  the  works 
was  to  pump  it,  and  all  the  materials  used  in  the  dam  were  sluiced  in  from 
a  neighboring  hill.  The  total  cost  of  the  work,  including  the  plant  and  all 
the  appurtenances  of  the  reservoir  in  the  way  of  gates,  outlet-pipes,  etc., 
was  but  4f  cents  per  cubic  yard.    The  dam.  Fig.  40,  is  575  feet  long  on 


LtSRARY 

Of  THE 
UNIVERSITY  of  ILUNOIl 


g  3 

3  3 
»  o 


CD 


LIBHAHY 

Ofr  THE 

UNIVERSITY  of  ILLIHOU 


HYDRAULIC-FILL  DAM-CONSTBUCTION. 


83 


top,  32  feet  high,  and  contains  24,000  cubic  yards,  the  inner  slopes  being 
3  on  1,  and  the  outer  2  on  1,  with  a  4-foot  berm  on  the  inside  10  feet  below 
the  top.  The  maximum  depth  of  water  is  26  feet;  the  reservoir  covers  177 
acres  and  impounds  576,800,000  gallons,  or  1770  acre-feet.  The  water 
used  in  sluicing  was  forced  through  a  6-inch  pipe  by  a  Worthington  steam- 
pump  of  750,000  gallons  daily  capacity,  belonging  to  the  old  city  pumping- 
station  situated  on  the  opposite  side  of  the  valley  from  the  hill  which 
supplied  the  material.  This  hill  is  150  feet  high,  and  the  pipe  terminated 
about  half-way  up  from  its  base,  where  a  common  fire-hydrant  was  placed 
to  which  was  attached  an  ordinary  2|-inch  fire-hose,  with  a  nozzle  of  1^ 
inches  diameter.  From  this  nozzle  the  stream  was  directed  against  the  face 
of  the  hill  under  a  pressure  limited  to  100  lbs.  per  square  inch  (Fig.  41). 
The  washing  was  carried  rapidly  into  the  hill  on  a  3^  up-grade  which  soon 
gave  a  working  face  of  10  feet  or  more,  increasing  gradually  to  36  feet 
vertical  height.  By  maintaining  the  jet  at  the  foot  of  the  cliff  the  latter 
was  undermined  as  rapidly  as  the  earth  could  be  broken  up  and  carried 
away  by  the  water.  The  material  found  in  the  hill  consisted  of  a  soft, 
friable  sandstone  infiltrated  with  ocher  of  varying  shades  of  yellow,  brown, 
and  red,  alternating  with  clay  and  sand,  the  whole  overlaid  by  a  surface 
soil  of  sandy  loam,  2  to  6  feet  deep.  Experiment  and  observation  led  to 
the  conclusion  that  65^  of  the  entire  mass  washed  into  the  dam  was  sand, 
and  35^  was  clay.  .  . 

In  beginning  the  work  a  trench  4  fe^t  wide  was  excavated  through  the 
surface  soil  down  into  clay  subsoil,  a  depth  of  several  feet,  and  this  trench 
was  refilled  with  selected  puddle-clay  sluiced  in  by  the  stream.  Then  the 
form  of  the  dam  was  outlined  by  throwing  up  low  sand  ridges  at  the  slope- 
lines,  which  were  maintained  as  the  dam  rose  in  height,  in  the  form  of 
levees  by  men  with  hoes  (Fig.  42).  A  shallow  stream  of  water  was  thus 
maintained  ov^r  the  top  of  the  embankment,  the  water  being  drawn  oft" 
from  time  to  time,  either  into  the  reservoir  or  outside,  as  preferred.  As 
the  embankment  rose  it  assumed  a  grade-line  from  the  side  nearest  to  the 
source  of  supply  to  the  opposite  side.  The  material  was  transported  from 
the  bank  in  a  13-inch  sheet-iron  pipe,  put  together  with  loose  joints,  stove- 
pipe fashion.  This  pipe  extended  from  near  the  face  of  the  bluff,  where 
the  jet  was  operating,  across  the  center  line  of  the  dam,  and  was  so  arranged 
as  to  be  easily  uncoupled  at  any  point,  so  as  to  direct  the  deposit  where 
required  to  build  up  the  embankment  uniformly.  When  the  end  of  the 
dam  nearest  the  bank  reached  the  full  height  the  pipe  was  raised  on  a 
trestle  to  give  it  grade  for  transporting  the  sand  to  the  opposite  side.  A 
spillway  was  cut  out  by  the  same  sluicing  process,  at  the  end  of  the  dam 
farthest  from  the  side  where  the  main  sluicing  operation  was  conducted, 
and  the  earth  from  it  was  also  placed  in  the  dam.  It  was  found  that  the 
quantity  of  solids  brought  down  by  the  water  varied  from  18^  in  clay  to 


84 


liESEliVOlRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


WOfo  in  sand.  Sharp  sand  does  not  How  as  readily  as  rounded  sand  or 
gravel,  and  is  improved  in  delivery  by  an  admixture  of  clay  and  stones.  In 
this  case  the  clay  acted  as  a  lubricant,  which  served  to  increase  the  carrying 
capacity  of  the  water. 

The  entire  volume  of  water  pumped  in  building  the  dam,  if  computed 
by  the  percentages  of  solids  given,  must  have  been  less  than  20,000,000 
gallons,  although  it  is  unlikely  that  these  percentages  were  maintained 
throughout.  The  volume  discharged  through  the  nozzle  under  the  stated 
pressure  must  have  been  about  1.4  second-feet,  which  is  a  very  small 
sluicing-head.  The  nozzle  velocity  was  115  feet  per  second.  The  limita- 
tion of  the  nozzle  pressure  to  100  lbs.  per  square  inch  restricted  the 
delivery  of  water  and  its  effective  power  in  disintegrating  and  transporting 
the  soil  to  considerably  less  than  might  have  been  accomplished  with  higher 
pressure. 

The  entire  cost  of  the  dam  with  all  its  accessories  is  said  to  have  been 
but  $1140,  which  must  be  regarded  as  a  marvel  of  cheapness  for  a  structure 
of  the  size  of  this  one  and  performing  the  function  of  an  impounding  dam 
of  its  magnitude.  Another  interesting  feature  connected  with  it  was  that 
the  consrruction  of  the  reservoir  permitted  the  new  pumping-station 
supplying  the  city  of  Tyler  to  be  located  on  the  border  of  the  pond  so  much 
nearer  to  the  town  than  the  location  of  the  original  pumping-plant,  which 
was  at  the  site  of  the  dam,  as  actually  to  save  the  cost  of  the  dam  in  the 
length  of  main  pipe  that  was  thereby  dispensed  with. 

The  average  cost  per  acre-foot  of  storage  capacity  in  the  reservoir  formed 
by  the  dam  was  but  10.65.  The  dam  is  reported  to  have  no  apparent 
defects  and  gives  satisfactory  service.  Mr.  L.  W.  Yfells  was  engineer  and 
foreman  in  charge  of  the  works,  from  whose  memoranda,  furnished  by 
courtesy  of  Mr.  Howells,  consulting  engineer,  the  foregoing  description  has 
been  compiled.  The  accompanying  illustrations  were  obtained  through  the 
courtesy  of  Mr.  Ben  K.  Cain,  of  the  Tyler  Water  Company. 

La  Mesa  Dam,  California.— In  the  spring  of  1895  the  San  Diego  Flume 
Company,  which  supplies  the  city  of  San  Diego,  California,  with  domestic 
water  and  furnishes  an  extensive  territory  of  agricultural  land  with  an 
irrigation-supply  through  a  long  line  of  flume,  built  an  impounding- 
reservoir  on  the  Mesa,  or  tableland,  8  miles  northeast  of  San  Diego,  near 
the  terminus  of  the  flume,  for  the  purpose  of  impounding  the  tail-water 
of  the  flume  and  the  surplus  accumulating  at  night,  as  well  as  to  store  the 
flood-water  of  the  San  Diego  Eiver  in  winter  to  the  extent  of  the  unused 
capacity  of  the  flume.  The  dam  (see  Figs.  43  and  45)  was  designed  and 
constructed  by  J.  M.  Howells,  C.E.,  who  was  then  president  of  the 
Flume  Company. 

With  the  successful  experience  obtained  with  hydraulic  dam -construc- 
tion at  Tyler,  Texas,  the  previous  year,  Mr.  Howells  applied  the  same 


HYDRAULIC-FILL  DAM-CONSTRUCTION. 


89 


methods  m  a  modified  form  to  the  erection  of  La  Mesa  dam.  The  situation 
and  materials  available  were  less  favorable  than  at  Tyler,  and  it  was  not 
possible  to  obtain  water  under  pressure  for  disintegrating  the  soil.  Hence 
it  was  necessary  to  resort  to  ground-sluicing  alone. 

The  dam-site  is  in  a  narrow  gorge  cut  through  hard  porphyry,  whose 
walls  are  but  40  feet  apart  at  the  stream-bed,  and  stand  nearly  vertical  on 
one  side  for  40  feet  in  height,  from  which  elevation  the  ground  slopes 
gently  upward  on  both  sides.    The  site  had  been  regarded  as  particularly 
suitable  for  a  masonry  or  rock-fill  dam,  as  the  foundations  were  of  the  best 
character  and  the  materials  at  hand  all  that  could  be  desired.    With  these 
advantages  in  view  the  first  plans  made  were  for  a  rock-fill  with  plank 
facing,  of  the  following  dimensions:  height,  55  feet;  length  on  top,  470  feet; 
thickness  at  base,  110  feet;  at  top,  12  feet;  upper  slope,  i  to  1 ;  lower  slope, 
1  to  1;  volume,  15,000  cubic  yards.    Bids  were  received  on  these  plans, 
the  lowest  of  which  called  for  99  cents  per  cubic  yard  for  the  rock-fill,  and 
12.08  for  dry  rubble  wall.    These  prices  are  but  55^  to  66^  of  the  contract 
prices  paid  for  the  Escondido  dam.    The  total  cost  under  these  bids  would 
have  been  120,260,  exclusive  of  the.  plank  facing  and  the  outlet-gates  and 
pipes.    The  hydraulic-fill  dam  proposed  by  Mr.  Howells  was  given  the 
preference  by  the  company  on  a  gnarantce  of  a  material  reduction  of  cost 
below  the  bids  for  the  rock-fill  dam,  and,  although  numerous  difficulties 
were  encountered,  it  was  finally  completed  for  about  $17,000,  including 
plant,  excavations  for  foundations  aud  spillway,  outlet-gates,  culvert  and 
stand-pipes,  paving  of  slopes,  and  all  accessories,  and  furthermore  it  was 
built  to  a  height  of  66  feet,  or  11  feet  higher  than  the  proposed  rock-fill. 
It  was  made  20  feet  wide  on  top,  with  a  base  width  of  251.5  feet.    All  of 
the  dam  except  a  few  feet  on  top,  which  had  to  be  finished  out  with 
wagons,  was  put  in  place  by  flowing  water.    The  surplus  water  from  the 
Hume  was  used  at  a  time  when  little  or  no  irrigation  was  going  on,  and  at 
the  same  time  the  water  was  stored  in  the  reservoir  as  it  was  being  formed 
back  of  the  dam. 

The  total  volume  of  material  handled  was  38,000  cubic  yards,  some  of 
which  was  transported  an  extreme  distance  of  2200  feet,  and  taken  from 
an  area  of  11.5  acres,  which  was  stripped  to  a  mean  depth  of  2  feet.  Had 
the  material  been  as  abundant  and  as  accessible  throughout  the  construc- 
tion as  it  was  up  to  the  time  one-fourth  of  the  dam  was  in  place,  the  entire 
structure  could  have  been  finished  for  25^  to  30^  of  its  ultimate  cost,  but 
unfortunately  it  was  found  that  below  a  depth  of  2  feet  from  the  surface 
the  gravel  and  cobblestones  of  the  mesa  were  cemented  together  so  hard  as 
to  resist  further  washing,  and  this  condition  necessitated  the  employment 
of  horses  and  scrapers  to  bring  much  of  the  material  used  to  the  sluiceways, 
at  greatly  increased  cost.  The  results,  considering  all  the  unfavorable  con- 
-ditions,  are  an  indication  of  what  can  be  accomplished  by  this  process  where 


90 


BESERV0IR8  FOR  IRRIGATION,  WATER-POWER,  ETC. 


surrounding  conditions  are  more  auspicious.  The  surface  soil  and  sand 
contained  in  the  coarse  gravel  constituted  less  than  one-third  of  the  mass, 
and  consequently  the  dam  can  properly  be  termed  a  rock-fill  with  an  earth 
core.  The  deposit  on  the  dam  being  always  near  the  outer  slopes,  the 
larger  stones  were  naturally  dropped  there,  while  the  finer  materials  shaded 
clf  towards  the  center.  The  gravel  is  of  all  grades,  from  egg  size  to  large 
cobbles,  8  to  10  inches  in  diameter.  On  the  outer  slopes  the  largest  of 
these  were  laid  up  in  a  dry  wall  of  uniform  slope  and  surface. 

In  beginning  the  work  a  trench  was  excavated  in  bed-rock,  as  shown  in 
Fig.  44,  from  2  to  5  feet  deep,  20  feet  wide  at  center  and  tapering  to  5  feet 
at  the  ends.  At  right  angles  to  this  trench  in  the  bed  of  the  gulch  a 
culvert  was  built  to  reach  entirely  through  the  dam  at  its  widest  point. 
This  culvert,  whose  details  are  shown  in  Fig.  45,  consisted  of  a  concrete 
conduit,  48  inches  wide,  30  inches  high,  extending  from  the  inner  face  of 
the  dam  outward  180  feet,  to  a  point  72  feet  from  the  lower  toe,  where  it 
connects  with  two  24-iQch  cast-iron  pipes,  that  form  the  outlet  to  the 
reservoir.  One  of  these  pipes  connects  with  a  wood-stave  pipe  supplying- 
water  to  San  Diego,  and  the  other  is  used  as  a  waste,  or  clean-out,  pipe. 
Both  are  controlled  by  gate- valves  at  the  toe  of  the  dam.  The  walls  of  the, 
concrete  culvert  are  12  inches  in  thickness,  and  four  vertical  stand-pipes 
connect  with  the  culvert  at  intervals  of  35  feet  from  the  inside  end.  These 
stand-pipes  consist  of  24-incli  vitrified  pipes,  surrounded  with  concrete, 
which  pass  upward  through  the  body  of  the  dam,  and  are  now  used  as 
outlet-pipes  to  the  reservoir  at  four  different  levels.  During  construction 
they  performed  the  important  function  of  conveying  the  water  into  the 
reservoir  after  it  had  dropped  its  load  of  gravel  and  sediment  on  to  the 
surrounding  embankment.  They  were  built  up  a  joint  at  a  time  in  2-foot 
sections,  as  the  work  progressed,  and  were  finished  off  at  the  top  with  brass- 
ring  and  flap- valve,  the  latter  being  controlled  by  rods  reaching  up  the 
slope  through  the  water  to  the  surface.  (See  Fig.  43.)  These  flap-valves  can 
only  be  opened  when  pressure  is  relieved  by  closing  the  gate-valves  below. 

The  volume  of  water  used  in  constructing  the  dam  was  from  300  to  400 
miner's  inches — 6  to  8  second-feet,  which  was  all  that  could  be  spared  from 
the  flume  after  supplying  the  domestic  consumption  in  San  Diego  and  along^ 
the  line,  and  the  little  irrigation  which  is  kept  up,  even  in  winter,  when 
the  rains  do  not  come  just  right.  From  the  end  of  the  37-niile  flume, 
which  terminates  on  the  mesa  10  miles  from  San  Diego,  the  water  was 
siphoned  across  a  deep  ravine  by  a  36-inch  wood-stave  pipe,  3000  feet  long, 
discharging  into  a  ditch  which  carried  the  water  1.5  miles  to  the  top  of  the 
ridge  overlooking  the  dam-site  on  the  south.  From  this  main  ditch  at 
various  points  laterals  were  carried  down  the  slope  of  the  hill  towards  the 
dam  on  a  grade  of  6^,  dividing  the  ground  into  irregular  zones  of  50  to  100 
feet  in  width,  by  several  hundred  feet  in  length.  In  sluicing  these  divisions 


94 


llEtiERVOIliS  FOB  limiQATlON,  WATEli-POWEU,  KTG. 


were  stripped  oli  clean  to  the  cemented  gravel  bed-rock,  beginning  next  to 
the  head  ditch  and  working  downward  toward  the  dam  across  the  end  of 
the  strip.  The  fall  from  the  npper-line  ditch  to  the  lower  side  of  the  zone 
was  as  great  as  the  slope  of  the  ground  would  admit, — the  greater  the  fall 
the  more  rapidly  the  sluicing  was  done.  The  work  accomplished  was  satis- 
factory as  long  as  this  slope  was  not  flatter  than  about  25^,  but  as  the  hill 
from  which  the  material  was  taken  rounded  oH  toward  the  top  the  velocity 
of  the  water  in  the  cross-ditches  became  lessened,  until  it  was  insufficient 
to  erode  the  material  from  its  bed,  and  the  process  had  to  be  assisted  by  the 
use  of  picks  or  plows,  where  the  ground  was  not  too  soft  for  teams  to  get 
over  it.  This  additional  labor  of  loosening  materially  increased  the  cost. 
All  of  the  material  was  obtained  from  one  side  of  the  dam,  which  was  a 
further  disadvantage. 

As  the  stream  secured  its  load  of  earth  or  gravel  it  was  conveyed  along 
the  line  of  the  lower  ditch  by  24-inch  wood-stave  pipes  until  deposited  on 
the  embankment.  About  2000  feet  of  this  piping  was  used  in  the  work, 
the  first  cost  of  which  was  90  cents  per  foot,  exclusive  of  the  lining  of 
strips  of  tire-steel  subsequently  added  to  resist  wear  and  tear.  It  was  made 
in  sections  of  10  to  14  feet,  loosely  placed  together  and  connected  by  strips 
of  canvas  wound  around  the  ends  of  abutting  joints  and  held  in  place  by 
an  ingenious  tourniquet  of  tarred  rope  placed  back  of  the  last  round  band 
on  the  end  of  each  section,  the  twist  on  one  being  made  by  a  long  nail,  and 
on  the  other  by  an  8- inch  piece  of  ^-inch  gas-pipe,  the  nail  slipping  into 
the  gas-pipe  and  so  preventing  both  ropes  from  loosening  or  untwisting. 
During  a  portion  of  this  work  the  pipes  were  supported  to  the  desired 
grade-line  on  the  dam  by  trestle-work.  A  wire  cable  was  also  used  for  this 
purpose,  although  the  latter  did  not  give  satisfactory  results.  Fig.  46  illus- 
trates both  methods  of  suspending  the  pipes,  and  shows  the  dam  when  about 
30  feet  high.  The  necessity  of  frequently  unjointing  the  pipe  on  the  dam 
for  distributing  the  material  evenly  over  the  line  from  side  to  side  made 
the  use  of  a  canvas  joint  over  that  portion  of  the  pipe  inconvenient,  and  it 
was  replaced  by  loose  straps  of  iron  bolted  to  the  pipes  on  the  sides, 
which  kept  them  in  line,  and  the  water  would  shoot  across  the  joint  with- 
out material  loss.  These  joints  were  easily  taken  apart  when  desired. 
The  pipes  were  found  to  wear  very  rapidly,  and  were  lined,  first  with  strips 
of  wood,  and  later  with  strap-iron  or  tire-steel.  Cast-iron  pipe  or  open 
flumes  would  be  preferable  for  this  sort  of  service. 

The  work  on  the  dam  began  February  14, 1895,  and  d  uring  the  first  thirty 
working-days,  of  24  hours  each,  21,000  cubic  yards,  or  6bfo  of  the  entire 
dam,  were  put  in  place — an  average  of  700  cubic  yards  per  day,  although  at 
times  more  than  double  this  amount  was  moved  in  24  hours.  The  ratio  of 
solid  embankment  to  water  used  during  this  period  was  about  3.3^.  The 
force  of  men  employed  varied  from  27  to  45,  working  in  eight-hour  shifts. 


i 


hydha  ulig-fill  dam-  constb  tjgtion. 


97 


Two  men  were  kept  on  the  dump  directing  the  stream  of  material  and 
building  up  the  outer  edges  of  the  slopes  to  the  proper  lines,  while  the 
others  were  chiefly  engaged  in  ground-sluicing.  With  looser  or  deeper  soil, 
dr  under  conditions  permitting  the  use  of  a  jet  of  water  under  pressure,  the 
cost  of  loosening,  which  in  this  case  was  the  chief  item  of  expense,  would 
6e  reduced  to  a  nominal  amount* 

It  is  apparent  that  an  embankment  built  in  this  manner  is  compacted 
as  thoroughly  as  it  could  be  by  any  process  of  rolling  and  is  not  subject  to 
further  settlement.  It  is  also  manifest  that  the  finer  materials  are  by  this 
process  precipitated  in  the  interior  of  the  fill,  next  to  the  discharge-outlets 
for  the  water,  and  that  the  particles  are  in  a  general  way  graded  in  size 
from  the  outside  toward  the  center.  In  this  dam  all  of  the  stand-pipes  are 
placed  inside  of  the  center  line,  as  shown  by  the  section  of  the  dam 
(Fig.  47),  and  therefore  more  of  the  coarse  and  permeable  bowlders  and 
gravel  are  placed  on  the  outer  half  of  the  embankment,  where  they  afford 


Fig.  47.— Cross-section  of  La  Mesa  Dam. 


ready  drainage  to  the  percolation  that  might  find  its  way  through  the  dam. 
(See  Fig.  47.)  Thus  the  failure  of  the  structure  through  the  ordinary 
process  of  supersaturation  and  the  sloughing  of  the  outer  slopes  is  rendered 
highly  improbable  if  not  impossible.  A  dam  built  in  this  way  is  tested  as 
it  grows  by  the  pond  of  water  standing  on  top  of  it  and  the  rising  lake 
behind  it,  and  if  any  weakness  exists  it  is  sure  to  be  discovered  and  remedied 
by  the  operation  of  natural  laws. 

This  dam  is  not  entirely  free  from  leakage,  although  as  the  water  comes 
through  quite  clear  it  causes  no  anxiety  and  shows  no  tendency  to  increase. 
The  leakage  measures  100  gallons  per  minute  when  the  water  in  the  reser- 
voir stands  at  the  54-foot  level,  and  23  gallons  per  minute  when  the  water 
stands  at  46  feet. 

The  reservoir-basin  is  large  enough  to  impound  18,890  acre-feet  if  the 


98 


RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


dam  be  raised  to  the  140-foot  contour.  Such  a  dam,  of  safe  dimensions, 
would  contain  682,000  cubic  yards,  and  its  construction  has  been  seriously 
considered,  the  material  to  be  obtained  by  excavating  the  interior  of  the 
basin,  conveying  it  to  the  dam  by  the  hydraulic  method  and  then  hoisting 
it  in  place  by  mechanical  means. 

The  elevation  of  the  base  of  the  dam  is  433.5  feet  above  sea-level,  and  a 
24-inch  wood-stave  pipe,  G500  feet  long,  banded  to  withstand  180  feet 
maximum  pressure,  connects  it  with  a  15-incli  steel  main  that  is  laid  from 
the  end  of  the  main  flame  to  San  Diego.  The  location  and  elevation  of  the 
connection  of  these  pipes  has  practically  determined  the  43-foot  contour  in 


Fig.  48.— La  Mesa  Hydkaulic-fill  Dam,  showing  Pipe  Discharging  Material 

ON  THE  Dam. 

tlie  reservoir  as  the  lowest  level  to  which  the  water  will  ordinarily  be  drawn 
when  used  for  city  service,  unless  a  more  direct  connection  be  made.  In 
times  of  scarcity  the  water  below  the  43-foot  level  has  been  pumped  Uom 
the  reservoir. 

Lake  Christine  Hydraulic-fill  Dam,  California. — Some  years  ago  the  San 
Joaquin  Electric  Company  erected  a  power-plant  on  the  San  Joaquin  River, 
34  miles  north  of  Fresno,  to  utilize  water  brought  from  the  North  Fork  of 
the  San  Joaquin  to  the  power  station.  The  power-drop  at  this  place  is 
1410  feet,  and  the  plant  is  remarkable  as  one  of  the  first  to  make  use  of  so 
high  a  drop,  as  well  as  for  the  long  distance  of  the  transmission  of  power, 
as  the  company  deliver  electricity  to  Hanford,  a  distance  of  70  miles,  as  well 


I 


HYDRA  ULIC-FILL  DA  M- GONSTIl  UGTIO N. 


101 


as  to  Fresno.  The  plant  was  designed  and  built  by  J.  J.  Seymour,  C.E., 
president  of  the  company,  and  by  J.  S.  Eastward,  chief  engineer,  under 
contracts  with  the  General  Electric  Company.  The  plant  was  entirely  suc- 
cessful until  the  recent  drouth  developed  such  an  unprecedented  shortage 
in  the  low-water  supply  as  to  diminish  the  possible  power  output  below  the 
demands  upon  it.  To  remedy  this  deficiency  the  company  is  engaged  in 
the  erection  of  a  storage-dam  for  impounding  the  flood  run-off  of  the  North 
Fork.  The  dam  has  been  planned  and  is  being  built  by  J.  M.  Howells, 
C.E.,  and  is  to  be  purely  of  the  hydraulic-fill  type.  The  general  dimen- 
sions are  as  follows: 


Maximum  height  lOQ  feet. 

Length  on  top   720  *' 

Slope  on  water-side.  2:1. 

"    "  lower  side  1.5  :  1. 

Width  of  canyon  at  base   30  feet 

Width  65  feet  higher  300  feet. 


Water  for  sluicing  is  brought  to  the  dam-site  a  distance  of  5  miles,  by 
flumes  and  ditches.    The  volume  used  is  15  second-feet  (750  miner's 
inches),  which  is  delivered  to  the  summit  of  a  hill  overlooking  the  dam  and 
200  feet  above  it.    This  hill,  which  is  to  furnish  the  materials  for  building 
the  dam,  has  been  surveyed  and  explored  by  borings  to  determine  the 
quantity  and  quality  of  available  earth  for  the  purpose.    The  hill  has  an 
underlying  base  of  granite,  which  has  disintegrated  very  irregularly,  leaving 
hard  exposures  at  various  points,  while  in  places  the  depth  to  solid  rock  is 
very  great.    This  disintegrated  material  is  sandy  in  places,  and  in  spots  it 
has  passed  into  the  clayey  stage,  while  fragments  of  granite  still  lie  bedded 
intact,  furnishing  rock  for  the  outer  paving  of  the  embankment.  Hard 
bed-rock  is  exposed  over  nearly  the  entire  area  covered  by  the  dam.    It  is 
of  granite  throughout,  hardest  near  the  level  of  the  stream,  where  erosion 
has  polished  it  smooth  and  glassy.    Higher  on  the  sides  it  is  not  so  hard, 
bat  will  make  an  excellent  foundation.    Advantage  has  been  taken  of  a 
cut,  blasted  out  from  the  solid  rock,  at  a  level  14  feet  above  the  stream-bed, 
by  an  old  mining  company  for  a  ditch  grade,  in  which  to  place  the  outlet' 
sluices.    This  cut  is  arched  over  with  masonry  for  the  entire  width  of  the 
dam,  and  will  serve  to  carry  the  flow  of  the  stream  during  construction. 
Gates  are  set  in  this  cut  on  the  center  line  of  the  dam,  to  be  closed  when 
the  dam  is  finished  and  storage  begins.    The  gate-stems  will  extend  up 
through  a  circular  shaft,  22  inches  in  diameter,  3  inches  thick,  reaching  to 
the  top  of  the  dam.    This  shaft  is  made  of  successive  rings  of  cemeat  pipo, 
12  inches  in  height,  which  are  added  one  at  a  time,  as  tlie  dam  rises! 
During  constrnction  this  shaft  will  serve  to  draw  off  the  surplus  water  from 


102 


liESERVOinS  FOR  lltUlGATION,  WATEIt-POWElt,  ETC. 


the  pond  formed  on  top  of  the  embankment,  after  its  load  of  material  has 
been  dropped  on  the  rising  dam. 

A  center  core  of  double  plank  sheeting  will  be  carried  up  through  the 
dam  from  bottom  to  within  10  feet  of  the  top,  and  throughout  its  entire 
length.  This  sheeting  will  be  embedded  in  concrete  at  bed-rock.  The 
concrete  will  be  made  of  high  grade,  thoroughly  rammed  and  water-tight 
on  the  upper  side  of  the  sheeting,  but  made  open  and  porous  on  the  lower 
side,  with  a  4-inch  pipe  molded  in  it  close  to  bed-rock  and  running  the 
entire  length  of  the  sheeting.  This  conduit  is  intended  to  drain  the  dam 
of  any  water  which  may  pass  through  seams  in  the  rock,  underneath  the 
dam,  or  leakage  through  the  puddle-core  in  the  center.  The  outlet  to  this 
drain  is  a  6-inch  pipe  of  cement,  laid  from  the  lowest  point  in  the  drain  to 
the  outer  toe  of  the  "dam. 

The  dam  will  be  composed  of  a  combination  of  rock,  gravel,  coarse  and 
fine  sand,  and  clay,  the  finer  particles  being  graded  by  the  varying  velocities 
of  the  water  and  deposited  in  the  center  of  the  embankment,  while  the 
coarser  materials,  and  fragments  of  granite,  up  to  12  inches  in  dimension, 
will  be  dropped  on  the  outer  faces  and  slopes.  This  method  of  filling  will 
more  perfectly  fill  all  tlie  voids  in  the  dam  than  any  other  possible  means. 
The  materials  will  be  transported  from  600  to  2000  feet,  and  deposited  on 
the  dam  by  the  agency  of  water  alone.  The  fineness  of  the  central  mass, 
and  its  impervious  character,  are  relied  upon  to  remain  constantly  moist  and 
free  from  air,  and  thus  preserve  the  wooden  sheeting  from  decay.  To  more 
thoroughly  mix  the  materials  of  the  puddle-core  and  break  up  a  tendency 
to  stratification,  it  is  proposed  to  draw  wagon-wheels,  properly  weighted, 
backward  and  forward,  parallel  with  the  central  sheeting,  during  construc- 
tion, by  means  of  a  wire  cable  and  capstans. 

The  dam  is  estimated  to  cost  but  125,000,  including  the  entire  cost  of 
the  flames  and  conduits.  Considering  the  remoteness  of  the  site  in  the 
mountains,  and  the  difficulty  involved  in  transporting  supplies,  this  cost, 
for  so  high  a  dam,  is  remarkably  low,  and  the  completion  and  test  of  the 
work  will  be  looked  forward  to  with  unusual  interest.  The  spillway  of  the 
dam  will  be  through  a  natural  gap,  located  800  feet  away  from  the  dam. 
This  spillway  will  be  100  feet  wide  at  the  90-foot  level,  and  225  feet  at  the 
100-foot  level. 

The  reservoir  will  have  a  length  of  3  miles,  and  an  average  width  of 
about  ^  mile.  Its  capacity  will  be  approximately  360,000,000  cubic  feet 
(8264  acre-feet),  which  is  estimated  to  yield  a  flow  during  low-water  period 
of  three  times  the  present  requirements  of  the  power-plant. 

Hydraulic  Fills  on  the  Canadian  Pacific  Railway. — Further  examples  of 
the  successful  employment  of  hydraulic  mining  principles  to  the  work  of 
building  embankments  are  to  be  found  on  the  Pacific  coast,  but  none  more 
instructive  than  the  extensive  hydraulic  fills  made  by  the  Canadian  Pacific 


HTDRA  ULIC-FILL  DAM-  CONlSTB  UGTION. 


103 


Eailway  in  British  Colambia,  where  trestles  of  great  height  are  being  sup- 
planted by  earth  and  gravel  embankments  made  by  the  agency  of  water 
4ilone.  The  methods  employed  differ  materially  from  those  described  in  the 
foregoing  pages,  but  will  doubtless  find  frequent  application  elsewhere  in 
irrigation-dam  construction. 

At  trestle  No.  374,  near  North  Bend,  in  Fraser  River  Canyon,  110  miles 
«ast  of  Vancouver,  there  was  required  to  fill  a  chasm  an  embankment  231 
feet  in  height,  containing  148,000  cubic  yards.  When  visited  by  the  writer 
iin  November,  1896,  the  fill  had  reached  a  height  of  167  feet  and  contained 
70,000  cubic  yards,  all  of  which  had  been  put  in  place  by  the  hydraulic 
process.  The  plant  used  consisted  of  1450  feet  of  double-riveted  sheet-steel 
pipe,  15  inches  in  diameter,  1200  feet  of  sluice-boxes  or  flumes,  about  3  feet 
wide  and  the  same  depth,  one  No.  3  double-jointed  Giant  "  monitor  with 
5-inch  nozzle,  and  a  large  derrick  fitted  with  a  Pelton  wheel  connected  with 
the  winding-drum  of  the  derrick  and  operated  by  diverting  the  jet  of  water, 
used  in  piping  the  bank,  upon  the  wheel  when  loads  were  to  be  hoisted  by 
the  derrick.  The  gravel  bank  where  the  material  was  obtained  was  1130 
feet  distant  from  the  center  of  the  track,  and  from  this  pit  the  pipe  was 
laid  to  an  adjacent  stream,  1450  feet,  in  which  length  the  fall  available  was 
125  feet.  The  sluice-boxes  were  laid  on  a  grade  of  11^  for  the  first  425 
feet,  increasing  to  25^  the  rest  of  the  way.  They  were  chiefly  supported 
on  trestles.  These  boxes,  constituting  a  continuous  flume,  were  paved  with 
wood  blocks  on  the  lighter  part  of  the  grade,  and  with  pieces  of  old  railway 
rails,  laid  close  together  lengthwise  of  the  flume,  where  the  grade  was 
heaviest. 

One  of  the  most  serious  difficulties  here  encountered — and  each  locality 
develops  its  special  problems— was  the  fact  that  about  50^  of  the  materials 
in  the  gravel-pit  was  such  as  to  be  classed  as  cemented  gravel;  20^  con- 
^sisted  of  bowlders,  too  large  to  pass  through  the  flume  and  requiring  to  be 
hoisted  out  of  the  way  and  piled  up  by  the  derrick;  while  but  30^  was 
loose  gravel,  of  the  character  best  adapted  for  the  work.  Notwithstanding 
these  disadvantages  the  results  accomplished  are  quite  remarkable,  as  the 
entire  cost  of  the  work,  including  the  plant,  was  but  $5089,  an  average  of 
7.24  cents  per  cubic  yard.  The  entire  force  employed  consisted  of  eight 
men,  disposed  as  follows:  1  piper  at  the  monitor,  1  man  at  the  head  of  the 
filuice-boxes  and  in  the  pit,  2  on  the  flume,  "  driving"  the  material  along 
to  prevent  choking,  3  on  the  dump,  distributing  the  material  and  making 
brush  mattresses  for  the  slopes,  and  1  foreman,  a  carpenter,  chiefly  engaged 
on  general  repairs  of  flume  and  overseeing  the  work.  The  time  occupied 
was  as  follows:  sluicing,  95.3  days;  removing  bowlders  from  the  pit,  50.4 
days;  repairing  flume  and  plant,  13.5  days;  total,  159.2  days  of  10  hours 
of  the  entire  force.  The  total  number  of  yards  moved,  divided  by  the  actual 
working-time  when  sluicing  was  in  progress,  gave  an  average  of  738  cubic 


101        BESEIlVOmS  FOR  IRRlOAriON,  WArER-POWEB,  ETC. 


yards  per  day  of  10  hours,  or  at  the  rate  of  1771  cubic  yards  per  24  hours. 
The  water  used  was  approximately  11  cubic  feet  per  second,  or  550  r/mer's 
inches  under  4-inch  pressure  (440  inches  under  G-inch  pressure),  the  duty 
performed  being  3.22  yards  per  24-hour  inch  under  4-inch  pressure,  or 
4.02  cubic  yards  per  inch  under  6-inch  pressure,  which  latter  is  the  unit  of 
measure  most  commonly  used  in  the  hydraulic  mines. 

.  Had  the  gravel-bank  been  free  from  large  bowlders,  the  work  could  have 
been  done  in  two-thirds  of  the  time  actually  occupied,  and  had  the  pressure 
been  greater  and  the  gravel  all  loose  instead  of  being  partially  cemented, 
requiring  the  use  of  explosives  to  loosen  it,  the  duty  of  the  water,  on  the 
high  grades  available  for  the  flume,  should  have  been  increased  more  than 
threefold,  as  the  ratio  of  solids  carried  was  only  about  hi  of  the  volume  of 
water  used.  An  understanding  of  all  these  conditions  suggests  what  might 
be  accomplished  by  this  rtiethod  with  a  perfect  combination  of  circum- 
stances, viz.,  water  under  pressure  of  400  to  500  feet  head,  loose  materials 
in  abundance  for  washing,  freedom  from  rocks  of  large  size,  and  heavy 
grades  to  the  dump. 

In  building  the  embankment  no  provision  was  made  for  draining  ofi  the 
water  down  through  the  center,  but  it  was  allowed  to  pour  over  the  slopes, 
which  were  protected  from  erosion  by  brush  and  tree-tops  woven  in  alter- 
nating layers  along  the  edges  of  the  fill.  Old  track-ties  and  poles  were  also 
used  with  the  brush.  In  addition  to  this  protection  it  was  necessary  to 
exercise  care  to  prevent  the  water  from  concentrating  in  channels  or  from 
reaching  to  the  sides  or  flowing  down  the  hill  over  the  natural  surface.  By 
keeping^the  sides  of  the  fill  as  nearly  level  as  possible  the  water  was  spread 
in  a  thin  sheet  over  the  face-slopes  and  reached  the  bottom  of  the  embank- 
ment without  washing  or  doing  injury.  The  slopes  are  remarkably  true 
and  uniform,  and  the  embankment  was  packed  very  hard,  particularly  near 
the  end  of  the  sluice,  where  the  gravel  had  dropped  from  a  considerable 
height  to  the  dump  below. 

The  device  employed  for  handling  the  bowlders  in  the  pit  by  water- 
power  was  ingenious  and  effective,  and  was  similar  to  those  in  common  use 
in  hydraulic  mines,  where  water  under  pressure  is  turned  at  will  upon  a 
tangential  water-wheel  with  peripheral  buckets.  This  wheel,  being  attached 
to  a  winding-drum,  the  wire  hoisting-rope  leading  from  the  derrick  boom 
is  rapidly  wound  up  and  the  load  bandied  at  will.  A  friction-brake  with 
long  lever  gave  the  operator  perfect  control  of  the  load  and  enabled  him  to 
lower  it  as  swiftly  or  as  gently  as  desired.  Sharp  turns  in  the  flume  were 
made  by  vertical  drops  of  2  feet  at  the  angle,  and  two  turns  of  90°  each 
were  thus  successfully  made. 

Bowlders  with  one  or  two  square  feet  of  face  would  sometimes  stop 
rolling,  and  if  not  quickly  started  would  cause  a  jam  and  overflow, 
endangering  the  flume  on  the  gravel  hillside.    Hence  it  was  necessary  to 


HYDBA  ULIC-FILL  DA  M-  C0N8TB  UGTION. 


105 


employ  two  "  drivers  "  to  patrol  the  portion  of  the  flupae  where  the  grade 
was  lightest,  to  keep  all  such  stones  in  continuous  motion.  On  the  heavier 
grade,  however,  no  such  attention  was  necessary. 

In  the  summer  of  1894  the  railway  company  made  a  similar  fill  of  66,000 
cnbic  yards,  at  the  crossing  of  a  stream  called  Chapman  Creek,  the  average 
cost  of  which  was  7.5  ceDts  per  cubic  yard,  of  which  3.2  cents  was  for 
plant.  The  actual  work  of  sluicing  was  but  1.78  cents  per  cubic  yard. 
In  this  case  also,  it  was  necessary  to  use  explosives  to  loosen  the  gravel  and 
prepare  it  for  washing. 

In  1897-98  the  same  company  made  a  similar  fill  at  the  crossing  of 
Mountain  Creek,  in  the  Selkirk  Mountains,  requiring  400,000  cubic  yards. 
(See  Fig.  50.)  The  total  length  was  10,086  feet  over  all,  with  extreme 
depth  of  154  feet.  The  fill  was  carried  up  on  a  slope  of  1^  to  1.  Between 
Aug.  10  and  Nov.  1, 1897,  over  65,000  cnbic  yards  were  sluiced  in  place,  at 


the  following  cost: 

Mattresses   11370.79 

Skiicing  labor   1195.96 

Mainteuance  and  repairs   678.90 

Superintendence  and  tools   385.05 

Total   $3630.70 


This  gives  the  average  cost  of  the  first  65,000  cubic  yards  at  5.59  cents 
per  yard.  Including  a  proportion  of  the  plant,  the  average  was  less  than 
8  cents  per  cubic  yard  of  embankment.  The  work  was  done  in  about  60 
working  days  of  10  hours  each,  and  the  average  was  nearly  1100  cubic  yards 
per  day.  The  Avater  was  delivered  to  the  nozzle  of  the  monitor  under  a 
head  of  160  feet,  the  diameter  of  nozzle  being  5.5  inches.  The  volume 
was  therefore  15.75  second-feet,  or  787  miner's  inches.  The  ratio  of  water 
to  gravel  was  as  19  to  1  and  the  duty  of  the  water  was  nearly  4.2  cubic 
yards  per  24-hour  inch  under  6-inch  pressure.  The  sluice-boxes  had  a 
grade  of  8/^.  The  water-supply  was  brought  in  a  flume,  4  feet  wide,  2  feet 
high,  2  miles  long,  built  on  a  grade  of  20  feet  per  mile.  The  entire  plant, 
including  roads,  camp,  stables,  flume,  pipe-line  1200  feet  long,  sluice-boxes 
600  feet  in  length,  etc.,  cost  $10,038.40.  Considerable  expense  was  caused 
by  snow  and  land-slides,  which  damaged  the  plant. 

The  trestles  were  filled  beginning  at  the  banks  of  the  stream  and  work- 
ing back  each  way.  On  the  made  bank  thus  formed  masonry  piers  were 
constructed,  and  a  steel  bridge  of  five  spans  was  built  over  the  main 
stream  between  them. 

The  work  has  been  planned  and  executed  under  direction  of  H.  J. 
Cambie,  Chief  Engineer  Pacific  Division,  Canadian  Pacific  Kailway,  and 
his  Chief  Assistant  Engineer,  Edmund  Duchesnay,  of  Vancouver,  B. C,  by 
whose  courtesy  the  data  concerning  the  work  have  been  supplied. 

The  class  of  work  done  on  the  Canadian  Pacific  Railway  described  in 


106         RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


tl]e  foregoing  pages  is  identical  with  that  which  is  required  in  dam- 
construction  with  similar  materials,  and  the  processes  employed  will  be 
recognized  by  engineers  as  distinctly  applicable  in  a  treatise  on  the  subject 
of  hydraulic  dam-building,  the  only  difference  being  that  in  railway  fills  no 
attention  is  paid  to  such  a  distribution  of  materials  as  will  secure  the  water- 
tightness  of  the  bank  and  free  drainage  of  percolating  waters  on  its  exterior 
SLirface. 

Hydraulic  Fills  on  the  Northern  Pacific  Railway. — The  cheap  and  effec- 
tive transportation  of  earth,  gravel,  rock,  and  sand  and  their  deposit  in 
embankment  by  water  at  a  cost  far  below  all  other  feasible  methods,  is  the 
main  principle  involved^and  this  principle  has  been  given  further  demon- 
stration on  a  large  scale  on  the  Northern  Pacific  Railway,  in  the  State  of 
Washingto-n,  during  the  years  1895-96-97.  No  less  than  fifteen  high  and 
dangerous  trestles  on  the  Cascade  Mountain  division  have  been  replaced  by 
hydraulic-made  embankments  of  earth,  gravel,  and  loose  rock,  washed  from 
the  adjacent  mountainsides.  The  total  amount  of  material  thus  moved 
aggregates  606,750  cubic  yards,  the  average  cost  of  which  was  6.39  cents  per 
cubic  yard;  or  5.82  cents  for  labor  and  0.57  cents  for  materials.  The  lowest 
cost  of  any  of  the  fills  was  3.38  cents  per  cubic  yard,  everything  included. 

The  average  cost  of  377,000  cubic  yards  was  4.79  cents  per  yard,  of 
which  the  detailed  cost  per  cubic  yard  was  as  follows,  figures  which  may  be 
of  special  interest  to  those  contemplating  similar  undertakings: 

Sluicing  and  building  side  levees   3.89  cents  per  yard. 

Hav  used  in  side  levees   0.09  " 

Tools,  0.08  - 

Lumber  and  nails   0.22    "  " 

Labor  building  fiumes   0.44    "      "  " 

Engineering  and  saperiuteudence   0.11    "      "  " 

Total   4^9    "  " 

This  work  was  done  in  the  midst  of  a  dense  forest,  where  the  ground  to 
be  sluiced  had  to  be  cleared,  and  stumps  and  roots  necessarily  interfered 
with  the  loosening  of  the  material.  All  of  the  377,000  yards  were  carried 
and  deposited  by  water  brought  to  the  pits  by  gravity.  In  one  case,  how- 
ever, that  of  bridge  191,  the  water  was  supplied  by  pumping  and  42,250 
cubic  yards  were  moved  by  water  thus  lifted  at  an  average  cost  of  13.5  cents 
per  cubic  yard,  the  detail  of  which  was  as  follows: 

■  Sluicing  and  building  leveea   10.81  cents  per  yard. 

Hay  used  in  side  levees   0.21    "      "  *' 

Tools   0.14 

Lumber  and  nails   0.12 

Labor  building  flumes  .  •  .  0.14 

Coal  used  in  pumping   1.87 

Engineering  and  superintendence   0,20 

Total   13.50 


I 


mmy 

Of  THE 

UH1^«HS^Ty.of.lLLlN0i^ 


HYDRA  ULIC-FILL  DA  M-  CONSTR  UCTIO  ZV. 


Ill 


The  plan  adopted  on  this  work  for  disposal  of  the  water  after  it  had 
accomplished  its  duty  was  practically  the  same  as  that  used  at  the  La  Mesa 
dam.  A  waste-box  (or  a  number  of  them  if  the  fill  was  a  large  one)  was 
taken  up  through  the  body  of  the  embankment,  and  built  up  a  little  at  a 
time,  as  the  filling  increased  in  height.  The  top  of  the  boxes  was  always 
kept  lower  than  the  side  levees,  so  that  the  water  could  escape  without 
overflowing  the  sides  as  in  the  case  of  the  Canadian  Pacific  fills.  Hay  or 
straw  was  used  for  the  side  levees  instead  of  brush  or  logs,  wliich  would 


Fig.  52. — Northern  Pactttc  RAn.wAT.    Bkidge  190. 


have  cost  considerably  more.  In  order  to  prevent  the  rapid  wearing  out  of 
the  bottom  of  the  flumes  a  paving  of  square  timbers  was  used,  cut  into 
3-inch  blocks,  so  that  the  end  would  be  presented  as  wearing  surface. 

It  was  found  that  grades  of  7€  and  preferably  8^  were  most  advan- 
tageous for  the  sluicing-flumes  to  carry  material  containing  considerable 
gravel  and  rock,  to  prevent  frequent  blocking  of  the  flumes. 

By  courtesy  of  E.  H.  McHenry,  Chief  Engineer,  and  Charles  S.  Bihler, 
Division  Engineer,  Northern  Pacific  Railway,  the  writer  has  been  furnished 
with  the  interesting  photographs  of  the  work  (Figs.  52,  53,  54.  and  55)^ 
which  illustrate  the  process  of  hydraulic  filling  very  clearly  in  all  its  phases, 
and  demonstrate  with  what  precision  embankments  can  thus  be  formed. 


112         RESEIIVOIRS  FOR  IRUIOAIION,  WATER-POWER,  ETC. 


The  following  general  description  of  the  work  from  the  pen  of  Mr.  Bihler 
is  appended : 

"  The  results  have  been  very  gratifying,  both  as  to  cost  and  character 
of  the  fills  made.  We  are  using,  or  trying  to  obtain,  about  100  inches  of 
water  for  each  nozzle,  as  with  a  less  quantity  the  rocky  character  of  the 
material  moved  does  not  give  good  results.  In  some  cases  we  have  been 
able  to  obtain  water  at  the  bridge,  without  the  necessity  of  building  any 
considerable  length  of  flames.  In  other  cases  we  had  to  construct  several 
miles  of  flames  for  the  water-supply.    These  flumes  are  constructed  in  the 


Fig.  53.— Nokthekn  Pacific  Railway.    Bridge  189,  Cascade  Mountaij^s. 


most  temporary  manner,  of  inch-and-a-quarter  lumber,  16  to  18  inches 
square.  Where  the  locality  would  permit  we  have  carried  the  dirt  to  the 
bridges  to  be  filled  a  distance  of  over  half  a  mile.  The  mauner  of  building 
up  the  fill  is  very  clearly  shown  in  the  photographs.  We  use  hay  for  keep- 
ing up  a  levee  on  the  outside,  and  wooden  frames  or  baffle-boards  which  are 
easily  moved,  to  deflect  the  main  current  from  the  levees.  The  waste-water 
is  taken  off  through  a  waste-box  which  is  taken  up  through  the  body  of  th3 
fill  and  built  up  as  the  filling  increases  in  height.  By  adjusting  the  height 
of  the  waste-gate  a  larger  or  smaller  amount  of  fine  material  can  be  retained 
in  the  fill,  as  desired.    In  building  up  the  fill  naturally  a  separation  of  the 


HYDHA  ULIC-FILL  DAM- CONSTB  UCTION. 


113 


materials  takes  place.  The  coarser  material  is  deposited  right  under  the 
end  of  the  sluice-boxes,  while  the  finer  material  is  carried  along  toward  the 
waste-boxes,  the  finest  particles  of  each  being  deposited  in  the  vicinity  oi 
the  waste-gate  in  the  shape  of  mud.  For  large  embankments  it  is  therefore 
necessary  to  have  several  waste-gates,  so  that  coarse  material  may  be 
deposited,  from  time  to  time,  at  those  places,  and  the  accumulation  of  too 
much  of  the  fine  material  at  any  one  point  may  be  avoided. 

"  The  plant  required  for  the  work  is  rather  inexpensive.  According  to 
locality,  one  nozzle  would  require  from  300  to  1000  feet  of  light  sheet-iron 


FiQ  54.— Northern  Pacific  Railway,  Hydraulic-fill  Construction.    View  tn 
Pit  showing  Hydraulic  Giant  in  Action. 


pipe,  costing  about  27.5  cents  per  foot,  and  a  No.  2  Giant,  costing  $95. 
Outside  of  this  nothing  is  required  except  picks,  shovels,  hoes,  and  axes. 

The  character  of  the  material  that  we  have  available  is  not  very  favor- 
able. The  pits  are  very  rocky,  and  the  banks  overlying  bed-rock  which 
can  be  loosened  by  the  water-jet  are  not  deep.  The  cost  given  for  sluicing 
and  building  levee  includes  all  costs  of  clearing.  From  five  to  six  men  are 
required  with  each  nozzle,  to  build  the  levee,  move  sluice-boxes,  and  do 
everything  else  connected  with  the  work." 


11 4:         RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


Following  is  a  summary  of  the  volume  and  cost  of  hydraulic  filling  as 
reported  to  date,  on  the  Northern  Pacific  Kail  way: 

Average  Cost  per  Yard. 


Bridge 

:             18,300  cubic  yards. 

b  21  ceiits. 

  6,200  " 

16.58  " 

167  

  24,500  " 

14.00  " 

<  ( 

170  

  30,800  " 

8.75  ' 

.  <( 

172  

  4,300  " 

10  55  " 

<  i 

173  

  9,700  " 

(( 

6  23  " 

  2,100  " 

( < 

13.25  " 

179  

  19,80.)  " 

9.31  " 

182  

  53,6U0  " 

3.b0  " 

i< 

  96,650  " 

4.34  " 

(< 

30  34  " 

<( 

186  /. 

  51,600  " 

<( 

7.02  " 

(( 

189  

.         .  158.100  " 

5.19  " 

<< 

190  

 128,800  " 

6.11  " 

<( 

13.50 

Pig.  55.— Northern  Pacific  Railway.  Bridge  184.   Hydraulic  Filling  in 

Progress. 


EYDBA  ULIC-FILL  DAM-  GONSTR  UCTION. 


115 


The  distinctive  advantage  recognized  in  favor  of  hydraulic  filling  of 
trestles  on  railways  is  that  it  can  be  carried  on  without  interruption  to  the 
traffic  and  without  endangering  the  trestle,  either  by  falling  rocks  or 
unequal  settlement,  and  when  it  is  completed  no  further  settlement  of  the 
embankment  can  occur.  The  latter  advantage  applies  with  special  force  to 
dam-construction,  and  is  one  whose  importance  can  scarcely  be  overesti- 
mated. Where  the  materials  available  consist  of  large  and  small  stones, 
either  angular  or  rounded  with  small  gravel,  sand,  and  silt,  the  ease  with 
which  these  materials  may  be  graded  and  assorted  so  as  to  permit  the  outer 
portion  of  the  embankment  to  be  built  of  the  coarser  rock  where  it  will 
afford  ready  drainage,  while  the  finer  particles  may  be  assembled  in  the 
center  and  inside  where  they  will  best  resist  percolation,  constitutes  a 
further  advantage,  which  may  well  be  considered  as  an  efficient  substitute 
for  the  ordinary  puddle-wall  of  earth  dams  built  in  the  usual  manner. 

OTHER  HYDRAULIC  CONSTRUCTIOl^. 

Seattle,  Washington. — ^Except  in  the  manner  of  loosening  the  materials 
and  putting  them  in  motion,  the  methods  of  hydraulic  construction  of 
embankment  described  in  the  foregoing  pages  are  quite  similar  to  those 
employed  in  the-  reclamation  work  done  by  the  Seattle  and  Lake  Washing- 
ton Waterway  Co.,  at  the  city  of  Seattle,  Washington. 

This  work,  however,  has  a  totally  different  object,  namely,  the  opening 
of  navigable  tidal  channels  by  dredging  and  the  reclamation  of  valuable  tide- 
lands  adjacent  to  the  business  center  of  the  city,  by  filling  them  with  the 
fine  black  sand  dredged  from  the  channels.  Two  powerful  suction-dredges 
were  used,  each  with  a  capacity  of  removing  6000  to  7000  cubic  yards  of 
solids  per  24  hours,  which  was  pumped  from  the  bottom  of  the  channel 
through  18-inch  pipes,  a  distance  of  2000  to  4000  feet,  and  deposited  to  a 
depth  of  18  or  20  feet  over  the  area  to  be  reclaimed.  Some  36,000,000 
cubic  yards  are  to  be  handled  in  this  way,  and  1500  acres  filled  in  solidly 
to  a  height  of  2  feet  above  high  tide.  The  actual  cost  of  this  class  of  work 
does  not  exceed  two  cents  per  cubic  yard. 

The  mean  velocity  maintained  in  the  delivery-pipes  was  13.5  feet  per 
second,  and  the  discharge  was  24  second-feet,  so  that  when  the  work  was  at 
a  maximum  the  percentage  of  solids  carried  by  the  water  was  9^,  although 
tests  have  shown  as  high  as  20^.  The  bulkhead  along  the  channels  which 
hold  the  sand  in  place  is  made  of  brush  mattresses,  while  the  temporary 
cross-levees  are  effectively  formed  by  the  use  of  coarse  hay,  straw,  or  swamp- 
grass,  precisely  as  used  on  the  Northern  Pacific  fills. 

Tacoma,  "Washington. — Hydraulic  filling  was  done  on  a  very  large  scale 
a  few  years  since,  at  Tacoma,  Washington,  with  salt  water  pumped  from 
Pnget  Sound.    The  wharves  in  front  of  the  city  were  located  near  the  foot 


116         liESiniVOIllS  FOR  lliltiaATlON,  WATER-rOWmi,  ETC. 

of  a  higli  bluff  of  glacial  drift,  and  it  was  desired  to  till  a  large  area  of 
lowland  approaching  the  wharves,  and  substitute  a  portion  of  the  wharves 
with  an  embankment  of  solid  ground.  To  do  this  work  the  pumped  water 
was  piped  against  the  bank,  which  was  undermined,  and  the  material 
carried  to  the  place  of  deposit  by  the  water.  The  cost  of  the  work  is  repre- 
sented to  have  been  very  low,  not  exceeding  six  cents  per  cubic  yard,  and 
che  object  sought  was  attained  with  entire  success. 

Holyoke  Dam,  Massachusetts.— The  Holyoke  dam,  across  the  Oonnecti- 
T»ut  River,  was  built  as  a  timber-crib  structure  1017  feet  long  and  30  feet 
high.  In  ]  885  the  dam  was  reconstructed  and  filled  with  a  mass  of  puddle- 
gravel,  washed  in  and  puddled  by  hydraulic  streams,  under  direction  of 
Mr.  Clemens  Herschel,  M.  Am.  Soc.  C.  E.,  of  which  he  writes:  "No 
part  of  the  work  gave  less  anxiety  and  more  satisfaction  than  this  from  the 
day  it  was  started."  Referring  to  similar  work  Mr.  Herschel  again  writes:  f 
*'  Pure  gravel,  just  as  it  comes  from  the  gravel-pit,  will  make  a  water-tight 
stop,  when  used  between  planks,  or  in  any  other  position  for  which  puddle 
is  used,  as  far  as  my  experience  goes,  better  than  clay  or  a  clay  mixture 
ever  did." 

Georgia. — In  the  course  of  an  extended  experience  in  hydraulic  mining 
on  the  Etowah  River,  in  Georgia,  Col.  Latham  Anderson,  M.  Am.  Soc. 
0.  E.,  demonstrated  that  "  Gravelly  hydraulic  tailings  could  be  deposited 
within  sharply  defined  limits  and  in  any  shape  desired,  limited  only  by  the 
condition  that  the  slopes  should  not  be  steeper  than  the  natural  repose  of 
the  material."    (Private  letter  to  the  writer.) 

Utah  Experiments. — The  experiments  made  by  Prof.  S.  Eortier,  of  the 
Utah  Agricultural  College  Experiment  Station,  on  the  mixture  of  various 
aggregates  for  use  in  construction  of  earthen  dams,  shows  that  gravel,  sand, 
and  clay  will  occupy  less  space  and  become  more  compact  when  poured  into 
water,  mixed  therewith,  and  allowed  to  drain  and  settle,  than  by  any 
process  of  tamping  either  moist  or  dry.]; 

These  miscellaneous  citations  sufficiently  illustrate  the  principles  and 
methods  that  may  be  successfully  employed,  in  any  locality  where  natural 
conditions  are  favorable  for  the  construction  of  dams,  safely,  cheaply,  and 
efficiently  by  the  powerful  and  convenient  aid  of  flowing  water. 


*  Trans.  Am.  Soc.  Civil  Eng.,  vol.  xv.  p.  568. 
f  lUd.,  vol.  xxvi.  p.  fi84, 

X  Earthen  Dams,  by  Samuel  Fortier;  Bulletin  Uiah  Agricultural  College,  No.  46, 
Nov.  1896. 


CHAPTER  nr. 


MASONRY  DAMS. 

The  character  of  structure  which  appeals  most  effectireW  to  the 
majorUy  as  worthy  of  confidence  in  its  ability  to  withstand  water-pressure 
and  the  action  of  tlie  elements  for  ages  is  unquestionably  the  masonry  dam 
founded  on  sol.d  rock  and  bnilt  up  as  a  monolith  between  the  natural  rock 
buttresses  of  a  gorge,  with  Portland-cement  mortar.    Such  a  structure 
mvanably  commands  greater  respect  and  confidence  in  the  public  mind 
than  any  other.    It  may  not  in  certain  cases  actually  be  .=afer  from  over 
turning  or  better  able  to  resist  the  strains  and  forces  tending  to  rupture  it 
than  well-bu,  t  dams  of  wood,  earth,  or  loose  rock,  but  it  usually  has  the 
appearance  of  strength;  and  the  moral  effect  of  a  dam  of  that  character 
upon  the  public,  as  well  as  upon  investors  in  securities  dependent  upon  the 
stability  of  dams  and  the  permanence  of  the  water-supply  retained  by  them 
in  reservoirs,  is  one  which  cannot  be  disregarded. 

Tliat  masonry  dams  are  not  built  in  every  site  is  due  to  the  fact  that 
the  foundations  are  not  always  suitable,  and  surrounding  conditions  often- 
times render  their  cost  prohibitive. 

Masonry  dams  are  distinct  from  buildings,  arched  bridges,  and  other 
masonry  structures  in  that  the  best  class  of  masonry  as  ordinarily  applied 
and  used  is  not  best  adapted  to  dam-construction.  Cut-stone  masonry  or 
ranged  ashlar,  while  more  expensive  and  of  greater  strength  than  is  not  so 
suitable  for  masonry  dams  as,  random  rubble,  laid  regardless  of  beds  or  courses 
homogeneous  concrete,  or  a  combination  of  large  irregular  masses  of  store 
embedded  m  concrete -a  rubble-concrete.-either  of  which  is  much 
cheaper.  The  strains  in  a  dam  are  in  various  directions,  whereat  rangeu 
ashlar,  laid  in  horizontal  courses,  is  best  adapted  to  resist  the  forces  acting 
perpendicular  to  those  courses,  and  not  those  having  the  same  horizontal 
direction.  The  dam  should  therefore  be  made  as  nearly  homogeneous  and 
monolithic  as  possible,  and  the  stones  used  thoroughly  interlocked  in  ail 
directions,  avoiding  the  horizontal  courses  of  ordinary  cut-stone  masonry 

While  masonry  dams  have  been  built  antedating  the  Christian  era  and 
some  very  notable  ones  were  constructed  in  Spain  for  irrigation-storage 
more  than  three  hundred  years  ago,  it  is  only  within  the  past  fifty  years 

117 


118         EESEEV0IR8  FOR  IRRIGAIION,  WATER-POWER,  ETC, 

that  the  correct  theories  of  the  straias  to  which  sach  structures  are  sub- 
iected,  and  the  proper  proportions  to  be  given  them  to  secure  stabihty 
under  all  conditions,  have  been  reduced  to  some  degree  of  mathematical 
certainty  The  Spanish  dams  built  in  the  sixteenth  century  were  massive 
blocks  of  masonry,  almost  rectangular  in  form,  containing  a  large  surplus 
of  material  beyond  actual  requirement,  but  so  unscientifically  disposed  as  to 
produce  maximum  pressures  dangerously  near  the  point  of  crushing. 

The  French  engineers  who  were  required  by  the  French  Government  to 
prepare  plans  for  high  masonry  dams  for  the  control  of  floods  on  torrential 
rivers  in  southern  France  about  fifty  years  ago,  were  the  first  to  advance 
new  ideas  and  practical  theories  on  the  principles  that  should  govern  the 
design  of  these  structures.    M.  SaziUy  prepared  a  paper  on  the  subject  in 
1853    and  a  few  years  later  the  matter  was  more  fully  elaborated  by 
M  Delocre,  on  whose  formula  were  drawn  the  plans  for  the  great  Furens 
dam  183.7  feet  high.   In  1881  Prof.  W.  J.  M.  Rankine,  the  noted  English 
engineer,  was  called  upon  to  report  on  the  best  form  of  masonry  dam  to  be 
built  for  the  city  of  Bombay,  India,  and  investigated  the  question  in  a 
thorough  mathematical  way,  producing  a  form  of  profile  which  is  recog. 
nized  as  one  of  the  most  logically  correct  in  its  conformity  to  all  requisite 
conditions.    He  established  as  one  of  the  governing  principles  that  no 
tension  strains  should  be  permitted  in  any  part  of  the  masonry,  and  that 
therefore  the  lines  of  resultant  pressure,  with  reservoir  either  full  or  empty, 
should  fall  within  the  inner  third  of  the  dam  at  all  points.    The  acceptance 
of  this  principle  carries  with  it  as  a  necessary  sequence  that  the  maxima 
pressures  will  fall  below  safe  limits,  whereas  if  the  dam  be  designed  with 
regard  to  safe  limits  of  pressure  alone  the  structure  may  be  so  slender  as  to 
carry  the  lines  of  pressure  far  beyond  the  center  third  and  thus  set  up 
dangerous  tension  in  the  masonry. 

Other  prominent  English  engineers  who  have  investigated  the  subject 
are  Mr  Guilford  L.  Molesworth  and  Mr.  W.  B.  Coventry. 

Mr  H.  M.  Wilson,  Assistant  Hydrographer,  U.  S.  Geological  Survey,  in 
his  "  Manual  of  Irrigation  Engineering,"  devotes  a  long  chapter  to  an  ad- 
mirable discussion  of  masonry  dams,  while  the  most  recent  American  treatise 
ia  the  elaborate  work  entitled  "  The  Design  and  Construction  of  Dams, 
by  Edward  Wegmann,  C.E.,  of  which  the  fourth  edition  was  issued  m  New 
York  in  1899  Mr.  Wegmann  has  rendered  invaluable  service  to  the  pro- 
fession in  the  investigation  of  the  difficult  problems  involved  in  the  design 
of  masonry  dams,  and  in  simplifying  the  mathematical  formula  for  com- 
puting the  economical  safe  proportions  of  such  structures. 

The  general  principles  to  be  considered  in  designing  such  a  dam  are 
briefly  as  follows: 

(1)  That  it  must  not  fail  by  overturning.  ,  .  .  ^ 

(2)  That  it  must  not  slide  on  its  foundation  or  on  any  horizontal  joints. 


MASONRY  DAMS. 


119 


(3)  That  it  mast  not  fail  by  the  crushing  of  the  masonry  or  the  settle- 

ment of  its  foundation. 

(4)  That  it  must  be  equally  safe  from  excessive  pressure  upon  the 

masonry  whether  the  reservoir  be  full  or  empty. 

(5)  That  certain  known  safe  limits  of  crushing  of  masonry  of  the  class 

to  be  used  shall  not  be  exceeded. 
Masonry  dams  may  resist  the  thrust  of  water-pressure  either  by  their 
weight  alone  or  by  being  built  in  the  form  of  an  arch,  which  will  transmit 
the  pressures  to  the  abutments.    The  first  of  these  two  classes  of  structure 
is  called  the  gravity  dam.    The  second  is  the  arch  dam,  and  it  may  be 
•either  of  the  gravity  type  in  arched  form,  or  it  may  depend  upon  its  arched 
iorm  alone.    In  either  case  the  weight  of  the  dam  must  be  borne  by  the 
foundations,  and  these  must  be  of  the  best  quality  of  solid  bed-rock. 
Everything  of  a  friable  nature  should  be  removed,  and  the  excavation  so 
made  as  to  leave  the  surface  rough,  to  avoid  the  possibility  of  the  dam 
sliding  on  its  base.    The  maxima  pressures  permissible  should  not  exceed 
15  tons  per  square  foot,  and  may  require  to  be  as  low  as  6  tons  per  square 
foot.    For  very  high  dams  it  is  essential  that  they  should  diminish  in  thick- 
ness as  the  top  is  approached,  else  the  masonry  might  be  crushed  and  fail 
of  its  own  weight.    This  consideration  suggests  the  simple  triangle  as 
theoretically  correct,  with  certain  modifications.    The  thrust  of  the  water 
tends  to  overthrow  the  dam  by  revolving  it  around  its  lower  toe,  and  hence 
there  is  such  a  concentration  of  water-pressure  and  weight  of  masonry  at 
that  point  as  to  necessitate  a  sufficient  width  of  base  to  confine  the  resultant 
of  these  forces  inside  the  outer  toe-line  of  the  wall,  and  avoid  the  crushing 
of  the  masonry  by  distribution  of  the  strains  over  a  greater  area.    If  the 
hypothenuse  of  the  right-angle  triangle  were  presented  to  the  water  as  the 
upper  face  of  the  dam,  the  forces  acting  perpendicular  to  that  face  would 
give  the  wall  greater  stability  from  overturning,  if  the  structure  were  con- 
sidered as  a  rigid  body  incapable  of  being  crushed.    On  the  contrary,  if  the 
vertical  side  of  the  triangle  be  presented  to  the  water,  the  dam,  while  less 
liable  to  be  overturned,  is  more  capable  of  resisting  fracture  or  crushing, 
the  pressures  are  more  evenly  distributed  over  its  base,  and  the  foundations 
less  likely  to  yield. 

While  the  simple  triangular  form  of  dam,  of  such  base-width  that  the 
lines  of  pressure  with  reservoir  full  or  empty  fall  within  the  inner  third, 
amply  fulfills  the  requisite  conditions  to  resist  the  quiet  pressure  of  water, 
in  practice  it  is  necessary  to  give  a  certain  definite  width  to  the  top  of  the 
dam  to  enable  it  to  resist  wave-action  and  ice-thrust.  In  dams  50  feet  high 
or  less  this  top  width  need  not  exceed  5  feet;  for  dams  100  feet  high  the 
width  need  not  be  more  than  10  feet,  and  for  a  height  of  200  feet  a  width 
of  20  feet  is  considered  ample.  Greater  widths  are  given  where  the  top  of 
the  dam  is  to  be  used  as  a  roadway.    The  crest  of  the  structure  should  also 


120         RESERVblliS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


be  raised  a  certain  elevation  above  the  highest  water-level  to  provide  for 
extreme  floods.  This  superelevation  will  necessarily  be  governed  by  the 
size  of  the  spillway  provided  and  the  area  of  watershed  tributary,  but 
onliuiirily  it  should  be  limited  to  about  10  feet  at  the  extreme. 

High  reservoir  dams  erected  across  large  streams,  where  conditions  do 
not  easily  permit  of  the  construction  of  a  spillway  to  carry  the  water  around 
them  and  it  is  necessary  to  permit  the  passage  of  floods  over  their  crest,  are 
subjected  to  shocks  due  to  the  weight  of  water  falling  upon  the  toe  of  the 
dam,  which  cannot  be  computed  accurately  and  for  which  no  formulae  have 
been  deduced.  In  cases  of  this  kind  it  is  customary  to  allow  a  substantial 
addition  to  the  dimensions  given  by  the  theoretical  profiles  deduced  from 
the  formulfe  for  gravity  dams  under  quiet  pressure,  and  to  provide  a  water- 
cushion  at  the  toe  of  the  dam  by  the  erection  of  an  auxiliary  wall  a  little 
distance  below.  The  lower  face  of  the  dam  should  also  conform  as  closely 
as  possible  to  the  natural  curves  assumed  by  the  falling  water. 

Curved  Dams— While  there  is  an  essential  general  agreement  among 
engineers  as  to  the  theoretical  profile  best  adapted  for  gravity  dams,  there  is 
a  wide  difference  of  opinion  as  to  the  effect  of  the  value  of  the  arch  in 
adding  stability  to  the  dam.  That  such  structures  can  and  do  successfully 
transmit  pressures  laterally  to  the  abutments  is  proven  by  the  Bear  Valley, 
the  Zola,  and  the  Sweetwater  dams  (Fig.  5G),  the  three  highest  and  most 


>S)nr££rxv^r£R  Dam 
Zola  Da/v? 

Fig.  56.-COMPAIUSON  of  Profiles  of  Zola,  j^weetwatee,  and  Bear  Valley 

Dams. 

noted  types  of  arched  dams  in  existence.  The  Bear  Valley  and  Zola  dams 
are  so  slender  in  profile  as  to  be  absolutely  unstable  were  they  built  straight, 
while  the  Sweetwater  dam,  though  more  nearly  approaching  the  gravity 
type,  is  of  such  proportions  as  to  be  theoretically  unstable  as  a  gravity  dam, 


MA80NBT  DAMS. 


121 


although  it  has  successfully  withstood  the  shocks  of  an  enormous  flood 
pouring  over  its  crest  for  nearly  two  days. 

M.  Delocre  has  said  that  a  curved  dam  will  act  as  an  arch  if  its  thick- 
ness does  not  exceed  one-third  of  the  radius  of  its  upper  face,  while  another 
emiuent  French  engineer,  M.  Pelletreau,  considers  that  it  will  so  act  pro- 
vided the  thickness  be  not  greater  than  one-half  the  radius.  Mr.  J.  B. 
Krantz  maintains  that  a  radius  as  small  as  65  feet  is  essential  to  permit  a 
dam  to  act  as  an  arch  and  transmit  water-pressure  to  the  sides.  All 
engineers  appear  to  agree  that  the  mathematics  of  curved  dams  are  extremely 
uncertain,  and  irreducible  to  a  satisfactory  demonstration.  It  is  un- 
doubtedly true  that  in  a  narrow  gorge  a  considerable  saving  of  masonry 
might  be  made  by  constructing  the  dam  as  an  arch,  with  equal  stability  to 
one  of  gravity  type  built  straight.  M.  Delocre  is  of  the  opinion  that  in  no 
situation  is  it  necessary  for  a  curved  dam  to  be  of  greater  thickness  at  any 
point  than  the  width  of  the  valley  at  that  lieight.  The  principle  now 
generally  adopted  as  safe  is  to  make  the  structure  strong  enough  to  resist 
water-pressure  by  its  weight,  and  curve  the  form  as  an  additional  safeguard. 

The  curving  of  all  dams  of  whatever  length  or  heiglit  regardless  of 
whether  they  may  act  as  an  arch  or  otherwise  for  the  pujpose  of  enabling 
them  to  better  resist  the  tendency  to  vertical  cracks  due  to  variations  in 
temperature,  especially  in  countries  subject  to  climatic  extremes,  is  coming 
to  be  recognized  as  of  sufficient  importance  to  lead  to  its  general  adoption. 
In  this  connection  the  following  quotation  is  taken  from  the  remarks  of 
Prof.  Forchheinier  of  the  Aix  la  Chapelle  Polytechnic  School,  Germany,  in 
discussing  a  paper  read  by  Mr.  George  Farren,  before  the  Institution  of 
Civil  Engineers,  in  1893,  on  "  Impounding  Reservoirs."  *  Referring  to  a 
dam  82  feet  high,  plastered  and  rendered  over  with  two  coats  of  asphalt, 
built  by  Prof.  Intze  in  Remscheid,  Westphalia,  Prof.  Forchlieimer  says: 

"A  backward  and  forward  movement,  amounting  to  1^-^  inches, 
occurred  daring  the  filling  and  emptying  of  the  reservoir,  and  the  move- 
ment due  to  temperature  was  almost  as  great  as  this.  The  latter  was  due 
less  to  the  temperature  of  the  air  than  to  direct  solar  radiation.  The  crest 
of  this  dam  was  460  feet  long  and  was  arched  with  a  radius  of  420  feet. 
One  side  was  exposed  to  the  sun  longer  than  the  other,  and  the  more  exposed 
part  moved  to  and  fro  seven-eighths  of  an  inch  in  the  course  of  the  year, 
while  the  other  part  moved  only  one-eighth  of  an  inch,  the  crest  expanding 
one  nine-thousandth  of  its  length,  or  five-eighths  of  an  inch.  In  arched 
dams  sach  movements  do  no  harm,  but  in  straight  dams  these  phenomena 
are  objectionable.  As  dams  are  usually  built  during  the  warmer  seasons  of 
the  year,  the  masonry  has  a  tendency  to  contract  in  the  colder  weather. 
In  a  curved  dam  this  can  take  place  by  movement  of  the  structure  without 
cracking,  but  not  in  a  straight  dam.  ...  If  the  temperature  is  lowered 


*  Proc.  Inst.  Civil  Eug.,  vol.  cxv.  p.  156. 


122        BESERVOIllS  FOR  IIUIIOATION,  WATER-POWER,  ETC. 

10°  C.  (18"  V.)  and  it  is  not  free  to  contract,  tension  amounting  to  between. 
140  and  280  pounds  per  square  inch  is  set  up,  which  is  greater  than  the 

mortar  will  stand  That  a  straight,  or  almost  straight,  wall  incurs 

considerable  danger  of  fracture  is  shown  by  practical  experience.  The 
dams  of  Habra,  Grands-Cheurfas,  and  Sig,  in  Algiers,  have  broken,  and  in 
that  of  Ilamiz  a  tear  occurred  during  the  first  filling.  The  Habra  dam 
broke  in  December,  and  the  Grands-Cheurfas  and  Sig  dams  gave  way  in  the 
month  of  February.  The  Beetaloo  dam,  in  Australia,  also  developed  a 
crack  one-eighth  of  an  inch  wide  in  the  middle  of  winter  without  any 
apparent  cause.  The  Mouche  dam.  Haute  Marne,  a  structure  1346  feet 
long  and  about  100  feet  high,  exhibits  clearly  the  dangers  attending 
straight  dams.  In  the  winter  of  1890-91,  when  the  temperature  varied 
between  -  10°  0.  and  -  20°  C.  (14°  to  -  4°  F.)  and  the  water-surface 
was  10  feet  8  inches  below  the  normal  level,  seven  vertical  cracks  appeared 
in  the  dam,  situated  at  uniform  distances  of  about  160  feet  apart.  They 
were  widest  at  the  top,  and  died  out  about  37  feet  below  the  normal  water- 
level.  Their  aggregate  breadth  was  2^  inches.  The  cracks  gradually  closed 
as  the  temperature  rose,  and  by  the  end  of  February,  1891,  four  of  them 
had  completely  vanished,  while  the  others  had  perceptibly  contracted." 

It  has  been  the  observation  of  the  writer  that  all  curved  dams  are  free 
from  cracks,  but  that  straight  reservoir  walls  are  quite  certain  to  crack. 
The  tendency  of  the  water-pressure  is  to  close  any  cracks  that  may  appear 
where  the  dam  is  curved,  and  a  curved  dam  is  able  to  take  up  the  move- 
ment due  to  temperature,  without  cracking,  even  though  the  pressure  may 
not  cause  the  arch  to  come  in  action.  The  inference  is  that  every  masonry 
dam  should  be  built  in  the  form  of  an  arch,  whatever  its  profile  may  be, 
for  the  avoidance  of  temperature  cracks. 

Mr.  H.  M.  Wilson  says:  *  "  An  additional  advantage  of  the  arched  form 
of  dam  is  that  the  pressure  of  the  water  on  the  back  of  the  arch  is  perpen- 
dicular to  the  up-stream  face,  and  is  decomposed  into  two  components,  one 
perpendicular  to  the  span  of  the  arch  and  the  other  parallel  to  it.  The 
first  is  resisted  by  the  gravity  and  arch  stability,  and  the  second  thrusts  the 
up-stream  face  into  compression,  which  has  a  tendency  to  close  all  vertical- 
cracks  and  to  consolidate  the  masonry  transversely.  An  excellent  manner 
in  which  to  increase  the  efficiency  of  the  arch  action  in  a  curved  dam  is 
that  employed  in  the  Sweetwater  dam.  This  consists  in  reducing  the 
radius  of  curvature  from  the  center  towards  the  abutments.  The  good 
effect  of  this  is  to  widen  the  base  or  spring  of  the  arch  at  the  abutments, 
thus  giving  a  broader  bearing  for  the  arch  on  the  hillsides.  The  effect  of 
this  is  seen  in  projections  or  rectangular  offsets  made  on  the  down-stream 
face  of  the  dam,  the  center  sloping  evenly,  while  the  surface  is  broken  by 


*  Manual  of  Irrigation  Engineering,  pp.  390,  391. 


THE  ^, 
lINJVtRSlTY  oflLUNOli 


MASONRY  DAMS. 


125 


steps  when  it  abuts  against  the  hillside.  .  .  .  Though  the  cross-section 
of  a  curved  dam  may  unquestionably  be  somewhat  reduced,  it  would  be 
unsafe  to  reduce  it  as  much  as  has  been  done  in  the  case  of  the  Bear  Valley 
and  Zola  dams,  though  these  hare  withstood  securely  the  pressures  brought 
against  them.  It  might  with  safety  be  reduced  to  tbe  dimensions  of  the 
Sweetwater  dam,  thus  saving  largely  in  the  amount  of  material  employed." 


AMEKICAl^'  DAMS. 


Old  Mission  Dam,  San  Diego,  Cal.— The  first  masonry  dam  built  in 
California  of  which  there  is  any  record  was  erected  in  1770  by  the  Jesuit 
Mission  Fathers.  It  was  constructed  across  the  San  Diego  Eiver,  13  miles 
above  its  mouth,  at  the  lower  end  of  El  Cajon  Valley,  where  the  stream 
cuts  through  a  dike  of  porphyry.  It  was  built  for  impounding  and  diverting 
water  for  irrigation  and  domestic  use  at  the  San  Diego  mission  4  miles 
below.  It  was  244  feet  in  length,  13  feet  in  thickness,  and  about  15  to  18 
feet  high.  Fig.  57  is  a  recent  photograph  of  the  old  dam  in  its  present 
condition,  half  buried  in  trees  and  driftwood.  The  view  is  taken  below  the 
main  outlet-sluice.  The  water  was  conveyed  to  the  mission  through  an 
open  masonry  conduit,  lined  with  semicircular  tile  or  half-pipes.  The 
cement  used  in  the  dam  was  made  from  limestone  possessing  hydraulic 
properties,  quarried  near  the  dam. .  -The  dam,  though  still  in  existence,  has 
been  disused  for  half  a  century  past.  It  shows  evidence  of  having  been 
damaged  by  floods  and  repaired  at  Various' times.  The  manual  labor  of 
construction  was  done  by  Indians,  of  whom  no  less  than  1600  neophytes 
were  at  one  time  supported  at  the  mission.  Considering  the  quality  of  the 
materials  and  labor  available,  and  the  torrential  nature  of  the  river,  which 
it  has  resisted,  as  evidenced  in  the  photograph  by  the  driftwood  piled  up 
against  it,  the  masonry  is  of  excellent  grade. 

El  Molino  Dam.— A  few  years  after  the  erection  of  the  Old  Mission  dam 
of  San  Diego  the  Jesuit  Fathers  constructed  a  masonry  wall  of  similar  size 
about  10  miles  east  of  Los  Angeles,  the  purpose  of  which  was  to  control 
and  raise  the  level  of  a  natural  lake  and  impound  it  for  use  in  irrigation  at 
the  Mission  San  Gabriel.  The  dam  is  located  on  what  is  now  known  as  El 
Molino  rancho,  the  name  being  derived  from  the  fact  that  the  priests  here 
built  a  mill,  whose  massive  walls  are  still  intact,  for  grinding  corn  and 
wheat,  the  power  for  which  was  derived  from  water  gathered  from  springs 
that  issued  from  the  hillside  and  fed  the  lake.  The  mill  was  a  little  above 
the  level  of  the  crest  of  the  dam,  and  the  water  from  the  wheels  flowed  into 
the  reservoir,  where  it  was  caught  for  use  in  the  valley  below.  The  dam 
was  straight  in  plan,  about  200  feet  long,  and  15  feet  high  at  the  center. 
The  masonry  is  of  superior  character  and  is  still  in  perfect  state  of  preserva- 
tion, although  it  has  not  been  in  service  as  a  dam  for  many  years  past. 


126         BESERVOJRS  FOR  IRRIGATION,  WATEli-POWER,  ETC. 


The  Sweetwater  Dam. — This  structure  is  located  in  the  Sweetwater 
River,  7  miles  above  the  mouth  of  the  stream  and  12  miles  southeast  of  tiio 
city  of  Sau  Diego,  California,  and  was  built  in  1887-88  by  the  San  Diego 
Land  and  Town  Company  to  impound  water  for  the  irrigation  of  lands 
bordering  on  the  bay  of  San  Diego  and  for  the  domestic  supply  of  National 
City.  The  Sweetwater,  like  all  the  so-called  rivers  of  San  Diego  County 
that  empty  into  the  Pacific  Ocean,  is  a  torrential  stream,  subject  to  violent 
floods  in  seasons  of  abundant  rains,  and  dwindling  to  a  diminutive  brook 
within  a  few  weeks  or  months  after  the- rain  ceases.  During  the  summer 
and  fall  it  ceases  to  flow,  and  on  occasional  years  of  low  rainfall  the  ran-off 
even  in  winter  is  practically  nothing,  so  that  it  was  essential  to  provide 
storage  for  at  least  two  years'  supply  for  the  territory  depending  upon  it. 
Prior  to  the  beginning  of  work  nothing  was  known  of  the  probable  run-oif 
to  be  expected,  further  than  that  the  watershed  area  of  186  square  miles, 
having  an  extreme  elevation  of  about  6000  feet,  would  probably  receive  a 
precipitation  very  greatly  in  excess  of  the  recorded  rainfall  at  San  Diego, 
where  the  record  has  been  maintained  for  nearly  forty  years,  and  that 
judging  by  this  record  the  run-off  from  such  a  watershed  should  give  an 
average  supply  adequate  to  the  needs  of  the  community  to  be  provided, 
with  a  storage  capacity  of  two  years'  supply  in  the  reservoir.  Subsequent 
experience  has  shown  that  the  fluctuation  in  run-off  has  ranged  from  prac- 
tically nothing  for  three  consecutive  years  to  70,000  acre-feet  in  one  year, 
or  nearly  four  times  the  reservoir  capacity,  per  annum.  At  the  time  the 
construction  of  the  dam  was  begun  in  November,  1886,  an  active  land 
"  boom  "  was  in  progress  in  southern  California,  and  the  San  Diego  Land 
and  Town  Company,  owning  a  large  area  of  fertile  lands,  found  them 
unsalable  without  water.  It  was  essential,  therefore,  to  obtain  a  certain 
portion  of  the  supply  quickly  in  order  to  market  the  lands.  The  dam  was 
thus  necessarily  planned  without  the  usual  preliminary  studies  of  its 
capacity  for  storage,  or  the  volume  of  supply  which  would  be  required  or 
could  be  made  available. 

As  originally  designed,  the  dam  was  to  be  a  slender  masonry  or  concrete 
structure,  fashioned  after  the  Bear  Valley  dam  by  the  same  engineer  who 
built  the  latter,  and  was  to  be  but  10  feet  thick  at  base,  3  feet  at  top,  and 
50  feet  high,  backed  on  the  water-face  by  an  embankment  of  quicksand. 
When  the  wall  had  reached  a  height  of  15  to  20  feet  at  the  highest  part,  at 
an  expenditure  of  135,000,  and  its  outline  and  design  were  fully  realized  by 
the  management,  the  plan  was  disapproved  and  the  writer  was  engaged  to 
construct  a  more  substantial  work  on  the  same  site,  utilizing  the  masonry 
already  in  place.  The  new  plan  was  drawn  to  have  an  extreme  height  of 
60  feet,  and  the  new  work  enveloped  the  old.  This  structure  is  shown 
nearly  complete  in  Fig.  58,  and  its  profile  is  shown  in  dotted  lines  in  the 
middle  section  on  Fig.  59.    It  was  built  in  steps  onthe  back  with  a  view  to 


130         liKSEBVOIRS  FOR  lliliia ATION,  WAl KR-POW  Kli.  ETC. 


iidding  to  its  height,  as  was  subseqr4ently  done.  The  dam  had  a  maximum 
thickness  of  35  feet  at  base,  and  was  5  feet  thick  at  the  top.  It  was  forti- 
fied by  an  embankment  of  clay  and  gravel  50  feet  wide,  10  to  15  feet  high, 


Fig.  60.— Face  of  Sweetwater  Dam  in  1899.    After  Two  Years  of  Drouth. 


placed  against  the  npper  side  and  well  tamped  in  place.  A  portion  of  this 
embankment  above  the  water-line  is  shown  in  Fig.  60,  a  view  taken  in  the 
summer  of  1899  when  the  reservoir  was  practically  empty. 

Shortly  before  the  completion  of  the  60-foot  dam  authority  was  given 
for  its  extension  to  90  feet  in  height,  on  the  recommendation  of  the  writer, 
whose  surveys  had  revealed  the  fact  that  the  reservoir  capacity  could  be 
increased  nearly  fivefold  by  such  addition  of  30  feet  to  the  height.  Accord- 
ingly excavation  was  renewed  at  the  lower  side  for  an  extension  of  the  width 
of  the  base,  and  work  proceeded  on  the  final  plan  without  interruption 
until  the  completion  of  the  entire  structure  in  April,  1888.  The  construc- 
tion occupied  sixteen  months  in  all,  including  two  months  of  waiting  for 
cement.    The  profile  adopted  is  shown  in  Fig.  59.    As  finished  the  dimen- 


sions were  the  following: 

Length  on  top   380  feet. 

"      at  base   150  " 

Thickness  at  base   46  " 

top   12  " 

Height  on  upper  side  exclusive  of  parapet   90  " 

Height  on  lower  side   98  " 

Kadius  of  arch   222  " 


MASONRY  DAMS. 


131 


The  up-stream  face  has  a  batter  of  1  to  6  from  base  to  within  6  feet  of 
top;  thence  vertical.  The  lower  slope  has  a  batter  of  1  in  3  for  28  feet, 
thea  1  in  4  for  32  feet,  and  thence  1  in  6  to  the  coping. 

Water  is  drawn  from  the  reservoir  through  a  tower  of  hexagonal  form, 
placed  50  feet  above  the  dam,  near  the  center  (see  Fig.  61),  and  connected 
with  the  dam  by  a  foot-bridge  of  iron  (see  Fig.  62). 

It  has  seven  inlet- valves  which  are  placed  at  intervals  of  10  feet  in 
height  from  the  top  down.  Two  cast-iron  outlet-pipes,  18  and  14  inches 
diameter  respectively,  lead  from  the  tower  to  and  through  the  dam.  They 
lie  in  a  trench  cut  in  the  bed-rock,  and  on  top  of  them  is  built  a  masonry 
conduit  from  the  tower  to  the  dam,  connecting  with  a  third  pipe,  36  inches 
diameter,  of  riveted  wrought  iron,  ^  inch  thick.  All  are  carefully 
embedded  in  the  masonry  of  the  dam,  and  no  leakage  has  ever  taken  place 
along  them.  Gate-valves  control  their  flow  below  the  dam.  The  tower 
valves  are  simple  plates  of  cast  iron  fitting  over  elbows  set  in  the  masonry 
of  the  tower,  and  can  only  be  moved  when  the  lower  gates  are  closed. 

The  stone  used  in  construction  was  quarried  from  the  cliffs  on  either 
side  below  the  dam,  within  a  distance  of  800  feet,  and  was  all  hauled  in 
wagons  and  stone-boats.  Animal  power  was  alone  used  for  manipulating  the 
derricks  in  the  quarry  and  on  the  dam,  as  well  as  for  mixing  concrete. 
The  stone  was  a  blue  and  gray  porphyry  impregnated  with  iron,  weighing 
175  to  200  pounds  per  cubic  foot.  It  quarried  out  with  irregular  cleavage, 
but  generally  presented  one  or  two  fairly  good  faces.  The  seams  in  the 
rock  contained  plastic  red-  clay  to  such  an  extent  that  it  was  necessary  to 
wash  and  scrub  by  hand  every  stone  that  went  into  the  dam  with  good  steel 
and  fiber  brushes.  Imported  English  and  German  cement  was  used 
throughout  the  work,  mixed  with  clean,  sharp  river  sand  in  a  revolving 
square  box  of  wood,  with  a  hollow  shaft  passing  through  two  diagonally 
opposite  corners,  through  which  the  water  was  introduced.  The  masonry 
weighed  when  tested  164  pounds  per  cubic  foot. 

The  waste-weir  is  formed  at  the  left  bank  as  a  part  of  the  dam,  and  as 
first  built  consisted  of  seven  bays,  each  4  feet  in  clear  width,  closed  with 
flash-boards,  which  could  be  opened  to  a  depth  of  5.7  feet  below  the  crest 
of  the  dam.  These  bays  were  separated  by  masonry  piers,  each  2  feet  in 
thickness.  This  wasteway  p.nd  a  30-inch  blow-off  gate  from  the  main  pipe 
below  had  a  combined  capacity  of  1300  second-feet,  which  was  in  excess  of 
the  maximum  flood  discharge  as  indicated  by  high-water  marks,  although  a 
subsequent  flood  exceeded  this  capacity  a  little  more  than  ten  times. 

The  volume  of  masonry  in  the  dam  proper,  including  the  parapet  3.5 
feet  high,  2  feet  thick,  was  19,269  cubic  yards.  The  wasteway,  inlet-tower, 
and  other  accessories  required  1238  cubic  yards  additional,  or  a  total  of 
20,507  cubic  yards  of  masonry,  in  which  were  used  17,562  barrels  of 


/ 


Fig.  61. — Details  of  Tower  of  Sweetwater  Dam. 


IISRARY 

■Of  THE 
tlNlVI^RSjTY^flLUNOli- 


UNtVE^SiTy^oflLLINOIi. 


MASONRY  DAMS. 


139 


cement,  an  average  of  1.17  cubic  yards  per  barrel.    The  total  cost  was 

$234,074.11,  divided  as  follows: 

Plant   16,236.76 

Materials   87,431.70 

Labor   140,405.65 

Total   1234,074.11 

The  reservoir  capacity  formed  by  the  dam  was  5,882,278,000  gallons  or 
18,053  acre-feet,  of  which  80^  is  within  the  tipper  30  feet,  and  40^  in  the 
last  10  feet.  The  area  covered  at  high-water  mark  was  722  acres,  of  which 
300  acres  was  cleared  and  grubbed  at  a  cost  of  $10,808.46,  or  about  $36  per 
acre.    The  average  depth  of  the  reservoir  is  25  feet. 

Enlargement. — On  the  17th  and  18th  of  January,  1895,  the  Sweetwater 
dam  successfully  withstood  a  test  far  more  severe  than  is  usually  imposed 
on  reservoir  walls  of  such  comparatively  slender  dimensions  (thanks  to  the 
painstaking  care  exercised  in  its  original  construction),  and  beyond  any 
previous  calculation  or  expectation.  On  those  dates  the  reservoir  was  filled 
to  overflowing  by  a  flood  resulting  from  a  rainfall  of  more  than  6  inches  in 
24  hours,  and  for  forty  hours  the  dam  was  submerged  to  a  maximum  depth 
of  22  inches  over  the  parapet  wall,  with  the  wasteway  and  blow-ofl  gate 
wide  open.  This  was  5.5  feet  higher^  than  the  water  had  been  expected  to 
rise  in  extreme  floods,  as  it  had  nofe  been'  cbiisidered  possible  for  the  crest 
of  the  parapet  to  be  reached. 

A  gap  in  the  ridge  to  the  south  of  the  reservoir,  the  crest  of  which  was 
about  level  with  the  parapet,  carried  off  quite  a  large  additional  volume  at 
the  extreme  of  the  flood.  The  maximum  rate  of  discharge  during  the  flood 
was  carefully  computed  by  Mr.  H.  N.  Savage  from  weir  measurement,  and 
found  to  be  18,150  second-feet,  a  rate  of  discharge  which  was  maintained 
for  one  liour. 

This  extraordinary  freshet,  which  within  a  week  produced  a  run-off  of 
nearly  three  times  the  capacity  of  the  reservoir,  was  gratifying  in  one 
respect,  in  that  it  demonstrated  the  ability  of  the  dam  to  cope  with  such 
emergencies,  as  not  a  stone  of  the  masonry  was  disturbed  or  moved  from 
place,  although  so  much  damage  was  done  to  the  pipes  and  surroundings  of 
the  dam  as  to  necessitate  a  larg€  expenditure  in  repairs.  The  water-supply 
was  cut  oti  from  consumers  for  more  than  a  month  before  a  partial  restora- 
tion could  be  made. 

Advantage  was  taken  of  the  opportunity  afforded  by  the  general  repairs 
to  make  a  material  enlargement  of  the  reservoir  capacity  by  virtually  raising 
*  the  permanent  high-water  level  to  the  point  it  had  assumed  during  the 
flood,  and  at  the  same  time  preparing  the  dam  for  receiving  a  repetition  of 
such  an  experience  by  enlarging  the  wasteway  and  fortifying  the  weak 
points  developed  by  the  flood. 


140         REBERVOmS  FOR  IRRIGATION,  WATEll-POWEli,  ETC. 


The  freshet  cansed  a  tremendons  erosion  of  the  bed-rock  on  either  side 
of  the  dam,  particularly  in  front  of  the  spillway  discharge,  where  the  strata 
were  inclined  at  about  the  proper  angle  to  enable  the  water  to  strip  olT  layer 
after  layer  with  surprising  rapidity,  it  was  estimated  that  no  less  than 
10,000  cubic  yards  of.  the  solid  rock  on  that  side  were  torn  away  and  washed 
down-stream,  and  some  2000  yards  from  the  opposite  wall  of  the  canyon. 
The  approach  of  a  disused  tunnel  below  the  spillway,  which  was  some  25 
feet  long,  and  about  30  feet  of  the  tunnel  itself,  in  solid  rock,  were  cut  off 
and  the  surrounding  rock  washed  away.  This  tunnel  had  been  opened 
some  years  before  to  draw  down  the  reservoir,  in  compliance  with  the  order 
of  the  United  States  Circuit  Court,  in  the  famous  litigation  over  the  con- 
demnation of  lands  in  the  reservoir-basin,  and  terminated  directly  in  front 
of  the  spillway  channel.  The  bombardment  of  the  stones  rolled  down  the 
canyon  during  the  flood  upon  the  pipe-line  resting  on  one  side  and  coverecl 
with  masonry,  destroyed  it  for  a  considerable  distance  down-stream,  as  well 
as  the  railway  track  leading  to  the  dam. 

The  repairs  to  the  dam,  and  the  general  improvements  designed,  were 
completed  in  the  summer  following  at  a  cost  of  130,000,  under  the  capable 
direction  of  H.  Savage,  chief  engineer,  the  writer  acting  as  consulting 
engineer  during  its  progress.    The  alterations  made  were  the  following: 

1.  The  parapet  of  the  dam  was  raised  2  feet  and  strengthened,  so  as  to 
permit  of  permanently  holding  the  water  in  the  reservoir  as  high  as  its 
crest,  leaving  200  feet  in  the  center  as  a  weir,  2  feet  deep.  This  weir  was 
arranged  with  cast-iron  frames  carrying  flashboards,  to  be  removed  in 
extreme  floods,  as  shown  in  Fig.  66. 

2.  The  spillway  was  extended  in  length  by  adding  four  more  bays,  each 
5  feet  wide,  and  carrying  all  the  bays  up  to  the  level  of  the  new  crest  of  the 
dam,  giving  it  a  maximum  depth  of  11.2  feet  and  a  discharging  capacity  of 
5500  second-feet. 

3.  The  unused  tunnel,  8  by  12  feet  in  size,  the  bottom  of  which  at  the 
head  is  50  feet  below  high-water  mark,  was  adapted  for  use  as  an  additional 
spillway  discharge,  by  laying  four  pipes  through  it  on  a  4^  grade,  two  of 
which  are  36  inches  and  two  30  inches  in  diameter,  all  arranged  with  valve 
covers  over  elbows  at  their  upper  ends,  where  a  shaft,  reaching  to  the  sur- 
face on  the  line  of  the  dam,  gives  means  of  control  (see  Figs.  68,  69,  and 
70).  Further  control  is  had  by  gate-valves  set  in  the  pipes  directly  below 
Ghe  masonry  bulkhead  built  across  the  tunnel  at  the  shaft,  all  the  pipes 
passing  through  this  bulkhead.  In  the  summer  of  1899,  when  the  reservoir 
was  empty,  the  head  of  this  tunnel  was  protected  by  a  concrete  portal  v/ith 
an  inclined  grillage  of  iron  rails  to  keep  out  drift,  as  shown  in  Fig.  70. 

4.  The  eroded  rock  slope  below  the  wasteway  after  being  made  uniform 
was  covered  with  a  grillage  of  iron  rails  embedded  in  concrete,  which  has  a 


THE 

UNIVERSITY  of  ILUNOk 


MASONRT  DAMS. 


145 


thickness  of  3  feet,  and  is  designed  to  prevent  all  future  erosion  of  the  beJ- 
rock  (Figs.  65  and  69). 

5.  A  concrete  wall  15  feet  high,  18  inches  thick,  with  counterforts  of 


Fig.  68. — Profile  and  Sectional  View  and  Plan  of  Wasteway  Tunnel, 

Sweetwater  Dam. 

15  feet  base,  was  built  from  bed-rock  50  feet  below  the  dam  on  a  curve 
concentric  with  it,  to  form  a  water-cushion  or  pool  in  case  of  a  future  over- 
flow.   This  is  shown  in  plan  in  Fig.  67. 


MASONRY  DAMS. 


14T 


6.  The  main  snpply-pipe  was  replaced  through  the  canyon  in  a  solid 
rock  cut  a  portion  of  the  way,  and  protected  throughout  the  canyon  by 
concrete  collars  and-covering  and  spur  walls,  all  with  iron  rods  incorporated. 

At  the  same  time  a  new  steel  pipe-line,  24  inches  in  diameter,  which 
was  partly  laid  when  the  flood  occurred,  was  completed  to  l^ational  City  on 


Fig.  70.— Sweetwater  Dam,  showing  Head  of  Outlet  Tunnel  and  Spillway. 


the  north  side  of  the  valley,  as  a  high-level  conduit.  This  was  connected 
with  and  took  supply  from  one  of  the  30-inch-diameter  pipes  built  in  the 
tunnel,  and  connected  with  the  original  distribution  system  at  National 
City,  thus  giving  two  independent  conduits. 

The  effect  of  raising  the  parapet  wall  in  the  manner  described  has  been 
to  raise  the  height  of  the  reservoir  5.5  feet  and  increase  its  capacity  about 
25^,  or  from  18,053  acre-feet  to  22,566  acre-feet.  The  dam  having  shown 
its  ability  to  withstand  this  increased  pressure,  it  is  now  proposed  to  make 
this  addition  to  the  reservoir  a  permanent  feature  of  the  works. 

Concrete  was  used  in  all  the  new  work,  as  preferable  to  rubble  masonry, 
because  of  the  greater  ease  with  which  all  the  materials  could  be  handled 
and  because  of  the  fact  that  the  work  could  be  performed  by  unskilled  labor 
under  intelligent  foremen.  The  concrete  was  mixed  with  a  rotary  Ransome 
mixer,  one  of  the  best  machines  for  the  purpose  yet  devised.  A  steam 
hoisting-engine  furnished  all  power  required  for  rock-crushing,  actuating 
the  mixer,  and  hoisting  the  concrete  to  the  top  of  the  dam,  where  it  was 
distributed  by  wheelbarrows.  Old  rails  and  scrap  bar-iron  of  all  sizes  were 
embedded  in  the  concrete  wherever  it  would  add  desired  reinforcement  to 
the  strength,  as  in  the  6-inch  floors  of  concrete  forming  the  foot-bridge 


148         RESERVOIRS  FOR  IRRIGATION,  WATER. POWJUR,  ETC. 

over  the  waste  way,  spanning  the  5-foot  spaces  between  piers;  in  the  roof  of 
the  giite-hoiise  over  the  sliaft  in  the  tunnel  from  which  the  lieavj  gates  ^ro 
suspended,  and  in  the  floor  of  the  house;  in  the  curved  wall  forming  the 
auxiliary  water-cushion  dam,  which  is  10  to  15  feet  high,  and  but  18  inches 
thick,  and  in  the  inclined  apron  of  the  wasteway.  This  construction  is 
quite  satisfactory,  and  shows  no  cracks  anywhere.  The  rates  of  expansion 
aud  contraction  of  iron  and  concrete  under  changes  of  temperature  are 
practically  identical,  and  no  separation  of  the  two  elements  can  occur  by 
such  changes. 

There  are  no  visible  evidences  of  cracks  in  any  of  the  masonry  of  the 
dam,  nor  any  indications  of  a  tendency  towards  crushing  at  the  toe  of  the 
dam.  This  may  be  due  to  the  fact  that  the  stone  is  extremely  hard  and 
strong,  and  the  mortar  of  prime  quality.  It  may  be  further  owing  to  the 
fact  that  arch  action  has  resisted  pressure  from  the  top  down  to  some 
neutral  point  where  gravity  alone  sufhces.  There  have  never  been  any 
spouting  leaks  to  indicate  the  transmission  of  an  upward  pressure  upon  the 
masonry  of  the  slightest  moment.  The  leakage  through  the  wall  was  never 
of  considerable  amount,  and  has  steadily  diminished,  so  that  when  full  the 
wall  is  practically  dry  over  most  of  its  outer  face. 

This  leakage  was  reduced  in  amount  in  1890  by  carefully  repointing  the 
inside  face  as  far  down  as  the  water  was  lowered  in  the  reservoir,  about  60 
feet  below  the  top,  and  applying  successive  washes  of  potash-soap  and  alum- 
water  alternating. 

Protracted  litigation  followed  the  building  of  the  Sweetwater  dam,  over 
the  attempted  condemnation  of  a  tract  of  about  300  acres  of  land  at  the 
upper  end  of  the  reservoir-basin,  submerged  by  the  impounded  water.  The 
land  was  comparatively  valueless  for  agricultural  purposes,  but  a  jury  gave 
an  exorbitant  judgment  of  its  value  on  testimony  erroneously  admitted  as  to 
its  special  adaptability  for  reservoir  purposes.  This  litigation  lasted  several 
years  and  was  finally  compromised,  but  the  effect  of  it  was  quite  disastrous 
to  the  progress  of  the  country  depending  upon  it  for  irrigation.  During  the 
progress  of  this  litigation  a  tunnel,  heretofore  referred  to,  was  opened 
around  the  south  end  of  the  dam,  at  the  level  of  25  feet  above  the  lowest 
outlet,  by  means  of  which  the  flooding  of  the  land  could  be  avoided.  In 
obedience  to  an  order  of  the  United  States  Circuit  Court- the  reservoir, 
which  had  been  fllled,  was  ordered  emptied,  and  an  enormous  volume  of 
water  was  thus  wasted  at  a  time  when  it  was  greatly  needed  for  irrigation. 

Including  the  period  of  retarded  growth  during  the  progress  of  litigation 
the  dam  has  been  in  service  for  thirteen  irrigation  seasons,  during  which 
time  the  impounded  water  has  created  values  aggregating  several  millions 
of  dollars,  reckoning  all  improvements  made  in  the  district  directly 
dependent  upon  it  for  water-supply.  The  area  irrigated  from  it  is  now 
4580  acres,  chiefly  planted  to  citrus  fruits,  of  which  the  greater  part  is 


'  —  MASONRY  DAMS.  Ii9 

devoted  to  lemons.  A  population  of  2500  to  3000  people  is  dependent 
upon  the  reservoir  for  domestic  water.  The  distribution  for  irrigation  as 
well  as  for  domestic  use  is  entirely  by  pressure-pipes,  and  the  agricultural 
community  is  as  well  equipped  for  fire-pressure  and  general  water-supply  as 
the  average  American  city.  All  water  for  irrigation,  and  practically  all 
domestic  water,  is  measured  by  standard  water-meters.  The  pipe  system 
has  cost  in  the  aggregate  some  $800,000. 

Run-off  of  Sweetwater  River. — The  area  of  watershed  above  the  Sweet- 
water dam  is  186  square  miles,  ranging  in  elevation  from  220  feet  above 
sea-level,  which  is  the  elevation  of  the  top  of  the  dam,  to  about  5500  feet 
at  the  summit  of  the  mountain-range  in  which  it  heads.  The  mean  eleva- 
tion of  the  basin  is  probably  about  2200  feet.  There  is  practically  no 
diversion  of  the  stream  above  the  reservoir,  and  no  utilization  of  its  water 
other  than  that  of  the  dam.  Hence  the  catchment  at  the  reservoir  repre- 
sents the  entire  run-off  of  the  shed.  A  careful  record  of  this  run-off  has 
been  kept  since  the  construction  of  the  dam.  Its  extremely  variable 
character  is  shown  by  the  following  table: 


Table  op  Measured  Run-off,  Sweetwater  Drainage-basin. 
Area  186  square  miles. 


Season. 

Rainfall  at 
Sweetwater  Dam. 
Inches. 

Run-off  as 
measured  at  the 
Dam. 
Acre-feet. 

Average  Yearly 
RuiJ-off  in 
Second -feet 

per  Square  Mile. 

Average  Annual 
Run-.ff. 
Second-feet. 

1887-88 

7,048 

0.0524 

9.74 

1888-89 

13.53 

25,253 

0.1875 

34.88 

1889-90 

16.52 

20,532 

0.1525 

28.36 

1890-91 

12.65 

21,565.5 

0.1602 

29.79 

1891-92 

9.88 

6,198.3 

0.0460 

8.26 

1892-93 

11.62 

16,260.7 

0.1210 

22.51 

1893-94 

6.20 

1,338.4 

0.0099 

18.45 

1894-95 

16.19 

73,412.1 

0.5452 

101.40 

1895-96 

7.29 

1,320.9 

0.0098 

1.83 

1896-97 

10.97 

6,891.6 

0.0512 

9.52 

1897-98 

7.05 

4.3 

0.00003 

0.006 

1898-99 

5  05 

245.5 

0.0018 

0.34 

1899-1900 

0.0 

0.0000 

0.00 

Total  

180,066.1 
13,851.2 

20.39 

Mean  for  13  vrs 

Of  the  entire  period  of  twelve  years  recorded  the  'run-off  has  exceeded 
the  capacity  of  the  reservoir  in  but  four  seasons.  The  remaining  eight 
seasons  have  been  so  far  below  the  full  reservoir-capacity  in  yield  of  stream- 
fiow  as  to  justify  the  recommendation  made  by  the  writer  on  the  completion 
of  the  dam  that  a  full  reservoir  should  always  be  considered  as  a  two-years' 
supply,  and  that  no  more  than  one-half  its  capacity  should  be  used  in  any 
one  season.  The  percentage  of  probable  mean  rainfall  which  this  run-off 
represents  is  remarkably  small,  in  view  of  the  mountainous  and  precipitous 


150         RESERVOIRS  FOR  niRWAT/OJV.  WATER-POWER,  ETC. 

character  of  a  considerable  part  of  the  drainage-basin.  The  mean  rainfall 
of  1894-95  was  estimated  at  27.14  inches,  of  which  the  rnn-olf  was  but 
2G^.  The  following  year,  with  an  estimated  mean  rainfall  of  10  inches  the 
run-off  was  bat  six-tenths  of  1^.  This  illustrates  the  great  variation  to 
which  such  streams  are  subject.  When  the  rainfall  in  the  lower  two-thirds 
of  the  basin  does  not  exceed  12  inches  it  is  all  absorbed  in  plant-growth  and 
evaporation  from  the  soil  and  does  not  feed  the  stream  except  when  it  comes 
in  violent  storms.  Under  such  conditions  the  upper  third  of  the  basin 
supplies  all  the  run-off,  and  if  that  portion  does  not  receive  more  than  18 
to  20  inches,  the  stream-flow  is  very  small  and  of  short  duration.  The 
record  of  catchment  at  the  Ouyamaca  reservoir,  whose  watershed  is  all  on 
the  mountain-top  from  4800  to  6500  feet  in  elevation,  adjoining  the  upper 
portion  of  the  Sweetwater  shed,  clearly  shows  that  the  larger  part  of  the 
run-off  of  all  of  these  coast  streams  must  ordinarily  come  from  the  higher 
mountains,  and  illustrates  the  value  of  elevation  in  any  shed  for  purposes 
of  yielding  run-off  for  reservoirs. 

The  precipitation  and  catchment  record  kept  at  the  Cuyamaca  dam 
from  1888  to  1896  shows  that  the  drainage-basin  of  11  square  miles  gave  an 
average  yield  of  491  acre-feet  of  water  per  square  mile,  while  the  mean  of 
the  Sweetwater  during  the  same  period  was  100  acre-feet  per  square  mile, 
or  about  one-fifth  that  of  the  Coyamaca. 

Since  the  great  flood  of  January,  1895,  the  Sweetwater  system  to  and 
including  1899  has  not  experienced  a  season  of  sufficient  run-off  to  fill  the 
reservoir,  and  has  endured  practically  four  years  of  continuous  drouth,  as 
the  entire  catchment  in  these  four  seasons  was  8,034  acre-feet,  or  36^  of 
the  reservoir  capacity.  As  a  result  the  reservoir  was  drained  to  the  bottom 
early  in  1899,  and  it  became  necessary  for  the  company  to  develop  and  put 
in  operation  an  entirely  new  and  independent  supply  for  the  preservation 
of  the  orchards.  Two  independent  gasoline-engine,  centrifugal-pump 
pumping-plants  were  established  in  the  bed  of  the  reservoir  about  1^ 
miles  above  the  dam,  by  which  water  was  drawn  from  35  small  wells  put 
down  in  the  shallow  sand  and  gravel-bed;  the  water  there  stored  in  the 
subterranean  voids  was  thus  made  to  yield  a  constant  flow  of  about 
1  second-foot.  This  was  conducted  in  a  flume  to  the  dam,  and  there 
admitted  to  the  tower  and  the  distributing  system.  The  pumping  was 
done  with  gasoline-engines,  the  lift  being  about  18  feet.  In  the  valley 
below  the  dam  three  substantial  pumping-stations  were  installed,  with 
steam-pumps,  drawing  from  a  large  number  of  wells,  bored  at  intervals  of 
100  feet  along  the  suction-pipe  leading  to  the  pump.  In  this  manner  the 
stored  water  in  the  sandy  bed  of  the  valley  was  made  to  produce  4  to 
5  second-feet  additional.  The  season  was  successfully  passed  owing  to  the 
energy  with  which  the  supply  was  developed,  the  orchards  were  kept  alive 
and  thrifty,  and  no  great  suffering  was  experienced,  although  it  seemed 


MASONRY  DAMS. 


151 


inevitable  at  the  beginning  of  the  irrigation  season  of  1899  that  the  orchards 
would  perish,  or  at  least  that  there  would  be  a  total  loss  of  frait,  if  not  of 
the  trees.  Pumping  operations  extended  from  May  to  November  23,  1899, 
during  which  time  the  total  volume  pumped  was  about  458,000,000 
gallons,  or  1402  acre-feet.  The  area  irrigated  was  approximately  3800  acres. 
Deducting  from  this  total  the  amount  of  water  used  for  domestic  service, 
the  mean  depth  actually  applied  to  the  orchards  averaged  3.|  inches! 
This  small  amount,  supplemented  by  thorough  cultivation,  proved  sufficient 
to  save  the  orchards  and  keep  them  in  healthy  growth,  which  is  an  in- 
teresting demonstration  of  what  can  be  done  in  an  emergency. 

The  cost  of  the  pumping-plants  and  wells  so  quickly  inaugurated  as  a 
substitute  for  the  reservoir  was  about  $27,000.  The  cost  of  pumping  was 
about  6^  cents  per  1000  gallons,  which  was  covered  by  an  increase  in  rates, 
to  which  the  community  cheerfully  acceded  as  an  emergency.  The  season 
of  1899-1900  having  failed  to  give  any  run-off  to  the  reservoir,  all  the 
pumping-plants  in  the  reservoir-basin  and  below  the  dam  were  reinstalled, 
and  an  auxiliary  plant,  consisting  of  40  wells,  2  inches  diameter,  50  feet 
deep,  pumped  by  a22-H.R  gasoline-engine  and  6-inch  centrifugal  pump, 
was  added  to  the  main  plant  at  Linwood  Grove,  while  at  Bonita  the  same 
number  of  wells  were  sunk,  and  pumped  by  two  6-inch  centrifugal  pumps, 
placed  in  tandem  and  actuated  by  gasoline-engines.  In  this  way  it  is 
hoped  to  tide  over  the  third  year  of  drouth. 

Sedimentation  of  Sweetwater  Reservoir.— Prior  to  the  construction  of 
the  dam  some  apprehension  was  felt  as  to  the  probability  of  the  speedy 
filling  of  the  reservoir  with  sand  brought  down  by  the  stream,  which  had 
been  thought  to  be  so  large  in  volume  as  to  destroy  the  usefulness  of  the 
reservoir  in  a  short  time.  The  writer  made  some  observations  on  the  load 
of  sediment  carried  by  the  stream  in  flood  during  the  construction  of  the 
dam,  which  led  him  to  conclude  that  the  reservoir  might  be  filled  with 
water  a  thousand  times  before  becoming  entirely  filled  with  sediment.* 

Careful  re-surveys  of  the  reservoir  made  by  Mr.  H.  N.  Savage,  chief 
engineer,  since  it  became  empty,  demonstrate  that  the  total  filling  has  been 
about  900  acre-feet  since  the  construction  of  the  dam,  or  at  the  average 
rate  of  75  acre-feet  per  annum.  The  total  volume  of  water  that  has  entered 
the  reservoir  in  twelve  years  has  been  180,066  acre-feet.  The  measured 
solids  deposited  from  this  water  have  therefore  averaged  a  trifle  more  than 
one-half  of  1^.  The  deposit  has  been  almost  directly  as  the  depth,  being 
greatest  at  the  dam,  where  the  depth  of  silt  of  almost  impalpable  fineness 
is  ^  to  3  feet.  The  addition  made  to  the  reservoir  capacity  after  the  flood 
of  1895  was  4.6  times  the  accumulated  sediment  of  twelve  years,  or,  in  other 
words,  sufficient  to  offset  the  filling  of  half  a  century. 

*^  The  Construction  of  the  Sweetwater  Dam.    TransTAm.  Soc.  Ci^dTEn^^^d^^ 


152         liI£SEBVOIBS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


Evaporation. — The  percentage  of  water  lost  in  storage-reservoirs  by 
evaporation  is  the  most  serious  factor  which  the  projectors  of  such  enter- 
prises have  to  anticipate.  It  is  subject  to  wide  variation  due  to  differences 
in  mean  depth,  exposure,  temperature,  witids,  and  relative  humidity,  but 
it  is  always  in  operation,  and  subjects  the  reservoir  to  a  constant  loss,  so 
great  that  it  must  be  considered  in  all  calculations  of  reservoir  duty,  as,  in 
■extreme  cases,  it  may  amount  to  50^  per  annum. 

Careful  measurements  of  evaporation  in  a  floating  pan  at  Sweetwater 
dam  shows  the  annual  loss  to  be  about  54  inches  in  depth.  It  is  about 
2  inches  during  the  month  of  January,  and  over  8  inches  per  month  during 
July  and  August.  This  causes  an  annual  loss  of  about  Ibfo  of  the  stored 
"water,  and  as  a  reservoir  must  always  be  held  back  for  dry  years,  so  that 
practically  a  reservoirful  is  at  least  a  two-years'  supply,  the  loss  is  really 
30^  of  the  total  supply,  leaving  but  70^  of  the  reservoir  capacity  available 
for  use,  one-half  of  which  only  can  be  safely  counted  on  each  year.  This 
reduces  the  available  annual  supply  to  about  8000  acre-feet. 

At  the  Cuyamaca  reservoir,  on  the  adjacent  watershed,  the  average 
loss  reported  during  nine  years  prior  to  1897  was  56f  inches  in  depth  per 
annum.  This  loss  amounted  to  25.5^  of  the  total  water  caught  and  stored 
during  that  time,  which  is  nearly  double  that  of  the  Sweetwater.  This 
difference  is  due  to  greater  surface  exposure  per  unit  of  volume  stored. 
The  Sweetwater  reservoir  has  an  exposure  of  39.8  acres  per  1000  acre-feet 
of  capacity  when  full,  while  the  Cuyamaca  has  an  exposure  of  84  acres  per 
1000.  This  is  an  illustration  of  the  advantage  of  great  average  depth  in 
reservoirs,  and  an  argument  in  favor  of  high  dams  for  effective  conservation 
of  water. 

Conduits. — The  main  pipe  leading  from  the  dam  is  36  inches  in  diameter 
for  1600  feet,  thence  30  inches  diameter  for  28,200  feet  to  Chula  Vista. 
It  has  a  minimum  capacity  for  delivery  of  1260  miner's  inches  (25.2 
second-feet)  to  an  elevation  of  90  feet  above  sea-level,  which  is  high  enough 
to  cover  the  larger  part  of  the  settlement.  This  pipe  was  found  to  be 
inadequate  to  the  demands  upon  it,  because  in  practice  the  maximum  rate 
of  consumption  is  about  double  the  mean  rate,  and  for  the  further  reason 
that  the  higher  levels  could  not  be  supplied  and  at  the  same  time  permit 
the  maximum  discharge  to  the  lower  levels.  To  remedy  this  lack  of 
efficiency  a  second  conduit,  24  inches  diameter,  was  built  in  1895  on  the 
north  side  of  the  valley  of  the  Sweetwater.  It  is  of  riveted  steel,  30,142 
feet  in  length,  and  cost  165,000.  It  has  a  minimum  capacity  of  450 
miner's  inches  (9  second-feet)  and  is  used  chiefly  for  high  service.  It  con- 
nects at  the  dam  with  one  of  the  30-inch  pipes  laid  through  the  tunnel. 
The  distributing  system  of  pipes,  from  4  to  24  inches  diameter,  is  over  65 
miles  in  length,  and  has  cost  over  half  a  million  dollars. 

Hemet  Dam,  California. — The  most  massive  and  imposing  structure  that 


MA80NBY  DAMS. 


153 


lias  thus  far  been  erected  in  western  American  for  irrigation-storage  is  the 
dam  erected  in  the  San  Jacinto  Moantains,  in  Eiverside  County,  California, 
at  the  outlet  of  Hemet  Valley,  the  location  of  which  with  respect  to  the 
irrigated  lands  is  shown  in  Fig.  71.  The  view  in  Fig.  72  is  rather  an 
imperfect  representation  of  the  appearance  of  the  dam  from  below.  Fig. 
I'd  is  an  end  view  which  shows  the  arched  form  of  the  dam. 

The  dam  is  built  of  granite  rubble,  laid  in  Portland-cement  concrete 
and  was  designed  to  be  carried  to  the  ultimate  height  of  160  feet  abo^e  the 
stream-bed.    Its  present  height  is  122.5  feet  above  base,  or  135.5  feet  above 


7j3.6S.fi.  /W 


To.es.R.eE 


6  S.  /?.  3E. 


Pig.  71.-MAP  showing  Location  of  Lake  Hemet,  the  Main  Conduit,  and  Irri- 

GATED  Lands 

lowest  foundations.    It  is  100  feet  in  thickness  at  base,  and  has  a  batter  of 
1  in  10  on  the  water-face,  and  5  in  10  on  back.    Its  present  crest  is  260  feet 
long,  while  the  length  on  base  is  but  40  feet.    The  dam  was  built  up  with 
tall  profile  to  the  height  of  110  feet  above  base,  at  which  point  the  thick- 
ness IS  30  feet.    Here  an  offset  of  18  feet  was  made,  and  the  remaining  wall 
IS  12  feet  at  base,  and  10  feet  thick  at  top.    A  spillway  notch  1  foot  deep, 
50  feet  long,  was  left  in  the  center.    Extreme  floods  may  exceed  the 
capacity  of  this  spillway  and  pass  over  the  entire  length  of  the  wall  to  the 
depth  of  several  feet.    This  actually  occurred  in  January,  1893,  when  the 
dam  was  107  feet  in  height.    The  dam  is  arched  up-stream  with  a  radius 
of  225.4  feet  on  the  line  of  its  upper  face  at  the  150-foot  contour,  althongh 
It  has  a  gravity  section,  with  the  lines  of  pressure  inside  the  center  third 
as  shown  on  section  in  Fig.  75.  ' 

The  site  seemed  to  be  more  suitable  for  a  masonry  structure  than  any 
other  type  because  the  canyon  is  extremely  narrow,  the  foundations  excel- 
lent  and  materials  for  construction  abundant.  After  due  consideration  of 
all  alternative  possibilities  the  writer  was  directed  to  prepare  plans  suitable 
for  the  maximum  height  to  which  a  dam  could  be  built  to  advantage  at  this 


164        EESEIiVOIliS  FOR  IRIUOATION,  WATER-POWER,  ETC, 


site,  and  in  the  summer  of  1890  the  plant  was  assembled  and  excavation 
begun.  The  stripping  to  bed-rock  occupied  several  months,  with  the  aid 
of  a  cableway  for  conveying  the  waste  to  a  dump  below  the  dam.  In  this 
operation  a  large  hole  was  developed  in  the  rock,  13  feet  in  depth,  within 
the  lines  of  the  base  of  the  dam.  This  hole  was  found  to  be  filled  with 
gravel,  firmly  cemented  in  place  so  tightly  that  it  might  safely  have  been 
built  upon  had  its  limits  been  known.  After  the  hole  was  cleaned  out  a 
center  trench  was  cut  in  the  bed-rock  up  the  sides,  as  a  key  or  anchorage, 
to  receive  the  masonry. 

The  cement  and  all  tools  had  to  be  hauled  up  the  mountain,  a  distance 
of  23  miles  from  the  nearest  railroad  station,  over  a  road  whose  maximum 
grade  is  18^,  making  a  total  ascent  of  3350  feet,  and  descending  to  the  dam 
from  the  summit  nearly  600  feet.  The  hauling  was  done  at  a  cost  of  II 
to  $1.50  per  barrel,  and  occupied  a  considerable  time  in  delivering  a  suffi- 
cient quantity  to  make  a  beginning,  and  it  was  the  5th  of  January,  1891, 
before  the  first  stone  was  laid. 

The  total  amount  of  cement  used  was  about  20,000  barrels,  which  cost 
delivered  about  15  per  barrel. 

Work  was  prosecuted  without  interruption  until  January  24,  1892, 
when  severe  weather  and  floods  compelled  a  suspension  of  construction  for 
four  months,  when  the  45-foot  level  was  reached. 

On  resumption  of  work  the  following  spring  it  was  pushed  to  the  107- 
foot  contour,  when  the  workmen  were  again  driven  off  by  a  storm  and 
freshet  on  January  9,  1893,  when  the  reservoir  was  filled  so  rapidly  that 
many  of  the  buildings  and  tools  were  submerged  before  they  could  be 
removed.  The  work  remained  at  this  stage  until  the  fall  of  1895,  when 
the  dam  was  completed  to  its  present  height  and  all  machinery  and  tools 
were  brought  down  the  mountain.  At  its  present  height  the  dam  contains 
31,105  cubic  yards  of  masonry. 

The  concrete  used  to  embed  the  blocks  of  stone  was  mixed  in  the  pro- 
portion of  1  of  cement,  3  of  sand,  and  6  of  broken  stone,  crushed  to  pass 
through  a  2i-inch  ring.  Mortar  was  only  used  in  laying  the  facing-stones 
and  pointing  the  joints  on  the  exterior  faces.  Both  concrete  and  mortar 
were  mixed  by  a  cubical  iron  mixer,  one  of  a  number  that  had  done  service 
on  the  San  Mateo  dam  in  northern  California.  The  sand  used  was  clean 
and  sharp,  and  was  constantly  brought  to  the  dam  by  the  small  living  stream 
flowing  from  the  mountains,  the  sand  being  rolled  along  its  bed.  It  was 
accumulated  in  a  little  reservoir  formed  by  a  temporary  log  dam,  and  con- 
veyed to  the  mixing-platform  by  an  endless  double-wire-rope  carrier,  fitted 
with  triangular  buckets,  placed  at  intervals  of  20  feet.  By  this  means  the 
sand  was  hoisted  125  feet  and  carried  horizontally  400  feet  to  the  mixing- 
platform,  where  it  was  stored  in  a  bin.  This  device  was  very  simple,  inex- 
pensive, and  quite  effective,  and  the  sand  was  always  washed  clean.  Fig. 


0^  THE 
UNlVERSITy  oflLUNOit 


01-  THE 
UNIVERSITY  of  ILLINOli 


MA80NBY  DAMS. 


159 


160         IIESEIIVOIRS  FOR  IIUilGATJOiV,  WATEltrOWmi,  ETG. 


76  shows  a  view  of  the  plant  for  crushing  the  stone  and  mixing  tha 
concrete.  A  portion  of  the  sand-conveyor  is  also  visible  in  the  photograph, 
as  well  as  one  of  the  engines  used  on  the  cable  ways,  and  the  cars  for  the 


Fig.  75.— Hemet  Dam,  Riverside  County,  California. 
delivery  of  concrete  to  the  dam.    These  latter  ran  along  a  tramway,  laid 
on  a  trestle  built  from  the  mixing-platform  along  the  face  of  the  vertical 
cliff,  some  300  feet,  to  the  dam  at  the  80-foot  level.    When  the  dam  reached 
this  level  an  elevator  was  built  to  a  higher  line  of  trestle. 


MASONRY  DAMS. 


161 


The  stone  was  all  quarried  within  400  feet  of  the  dam,  on  both  sides  of 
the  canyon,  both  above  and  below  the  dam.  It  was  hoisted  and  conveyed 
to  the  wall  by  two  cableways,  each  about  800  feet  long  and  1^  inches  in 
diameter.  The  cables  crossed  the  dam  nearly  at  right  angles  with  the 
chord  of  the  arch,  but  diverging  from  each  other,  and  were  anchored  to 
convenient  trees  on  either  side  of  the  gorge.  Their  position  was  seldom 
changed,  except  to  lift  them  higher  up  into  the  tree-tops,  and  to  erect  "  A  " 
frames  on  top  of  the  masonry  to  support  the  cables,  when  the  wall  had 
reached  such  a  height  as  to  require  it.    Loads  of  10  tons  could  be  hoisted 


Fig.  70. — Hemet  Dam  Construction  Plant. 


and  handled  with  ease,  and  with  the  aid  of  two  derricks,  one  at  each  end  of 
the  dam,  the  rock  brought  by  the  cables  was  placed  where  required.  The 
loads  were  readily  transferred  from  the  cableway  to  the  derricks  while  in 
the  air.  The  trolley  which  traveled  on  the  cableway,  and  the  devices  for 
sustaining  the  hoisting-line  as  the  load  moved  back  and  forth,  were  devised 
on  the  ground  and  operated  satisfactorily. 

The  derricks  were  actuated  by  water-power  obtained  from  a  36-inch 
Pelton  wheel  located  below  the  dam  and  propelled,  under  a  head  of  75  feet, 
by  about  80  miner's  inches  of  water,  brought  from  the  stream  by  a  flume 
1.5  miles  long  to  the  edge  of  the  cliff  at  the  mixing-platform,  and  thence 
in  a  13-inch  riveted  steel  pressure-pipe.  The  pipe  passed  through  the  line 
of  the  dam  and  was  embedded  in  the  masonry.    Subsequently  it  was  cut 


1G2 


llhJSERVOinS  FOR  IIUUGAIION,  WATER-POWER,  ETC^ 


oil  at  the  upper  face  of  tlie  dam  and  was  made  available  as  the  lowest  outlet 
of  the  reservoir.  Two  other  outlets  were  provided,  consisting  of  22-inch 
lap- welded  steel  pipes,  placed  at  the  45-foot  and  75-foot  levels,  near  the  left 
wall  of  the  canyon.  These  pipes  were  provided  with  cast-iron  elbows 
turning  upward  and  flaring  to  30  inches  diameter,  just  inside  the  line  of 
the  dam.  They  are  closed  by  semi-spherical  cast-iron  covers,  which  are 
raised  and  lowered  by  wire  ropes  passing  over  a  palley  and  windlass  that  are 
provided  for  each,  and  stand  on  an  overhanging  frame  bolted  to  the  top  of 
the  masonry.  These  covers  are  ordinarily  removed  and  replaced  by  cylin- 
drical fish-screens  that  stand  on  the  top  of  the  elbows,  and  the  main  control 
is  had  by  gate-valves  set  on  each  pipe  at  the  lower  line  of  the  dam.  When 
these  valves  are  open  the  water  spouts  freely  into  the  air  and  falls  in  a  spray 
upon  the  rock  below.  This  water  is  collected  in  a  pool  a  short  distance 
from  the  dam,  and  passes  over  a  weir  for  measurement,  before  beginning 
its  5-mile  plunge  down  the  canyon,  to  the  final  point  of  diversion  into  the 
main  flame. 

When  construction  began,  the  reservoir-site  was  well  covered  with  pine 
forest,  and,  as  it  was  desirable  to  clear  the  flowage  tract,  the  trees  were  cut 
and  sawed  into  lumber.  Over  one  million  feet  B.M.  of  this  lumber  was 
used  for  buildings,  flumes,  and  staging  about  the  dam,  and  half  a  million 
more  was  hauled  to  the  valley  for  flames  and  trestles.  Much  of  the  fire- 
wood cut  from  the  tree-tops  was  also  hauled  down  the  mountain  by  the 
retarning  cement  teams.  The  main  condait  is  partly  built  of  this  mountain 
pine,  and,  although  it  is  knotty  and  inferior  lumber  for  general  purposes, 
the  flume  made  of  it  did  good  service  for  six  or  eight  years  before  it  was 
recently  replaced  with  California  redwood,  which  is  much  more  durable. 
The  conduit  is  3.24  miles  in  length  from  the  pick-up  weir,  just  above  the 
junction  of  South  Fork  and  Strawberry  Fork,  to  the  mouth  of  the  main 
canyon,  where  it  connects  with  a  22-inch  riveted  iron  pipe,  2  miles  long. 
From  the  end  of  this  pipe  an  open  ditch,  lined  with  masonry  8  to  10  inches 
thick,  and  plastered  with  cement  mortar,  conveys  the  water  5  miles  to  a 
20-acre  distributing-reservoir,  located  near  the  highest  corner  of  the  irri- 
gated lands.  This  reservoir  has  a  capacity  of  about  90  acre-feet,  and  from 
it  the  water  is  distributed  by  some  30  miles  of  pipe,  flames,  and  lined 
ditches.  The  slope  of  the  land  is  40  feet  per  mile  from  east  to  west, 
requiring  small  conduits  for  distribution.  The  main  canyon  flume  was 
built  of  1^-inch  lumber,  and  is  38  inches  wide,  18  inches  deep,  and  has  a 
grade  of  about  140  feet  per  mile.  It  was  calked  and  battened,  smeared 
with  asphalt  inside,  and  whitewashed  on  the  exterior  with  lime.  The  ditch- 
lining  consists  of  granite  cobbles  of  10  inches  maximum  diameter,  laid  in 
equal  parts  of  lime  and  cement  mortar.  It  is  2. 75  feet  wide  on  bottom, 
7  feet  at  top,  2.75  feet  deep,  and  has  a  capacity  of  60  second-feet  or  3000 
inches. 


MASONRY  DAMS. 


163 


The  dam  of  the  distribating-reservoir  is  of  earth,  300  feet  long,  14  feet 
high,  and  8  feet  wide  on  top.  The  reservoir  is  usually  filled  within  a  foot 
of  the  top  of  the  dam.  In  construction  a  trench  was  excavated  9  feet  deep 
under  the  center  line,  in  the  center  of  which  a  tight  board  fence  was  built, 
reaching  to  the  top  of  the  dam,  to  prevent  the  burrowing  of  ground- 
sqairrels  and  gophers^  a  function  which  it  effectually  performs.  The  trench 
was  refilled  with  puddled  soil  each  side  of  the  fence,  and  the  puddle  brought 
to  the  top  of  the  dam.  The  area  irrigated  by  the  system  in  1896  was  1092 
acres,  and  is  increasing  each  year  as  the  tracts  are  sold  to  settlers. 

This  area  was  in  72  separate  tracts,  of  which  the  average  size  is  10  to 
20  acres.  The  rates  charged  for  water  are  $2  per  acre  annually,  with  an 
additional  charge  during  the  nominal  "  non-irrigating  season"  (November 
15  to  April  15)  of  II  per  month  for  each  tract  for  domestic  service.  In 
the  town  of  Hemet,  which  is  supplied  by  the  same  system,  there  were,  in 
1896,  55  taps,  paying  a  uniform  domestic  rate  of  $1.50  per  month.  Water- 
power  is  used  in  the  town  to  drive  an  electric  dynamo  for  lighting  the  hotel 
and  some  of  the  buildings,  the  waste  water  flowing  to  a  small  reservoir. 

The  apportionment  of  water  by  the  water-right  contracts  given  with 
the  deeds  to  the  land  is  at  the  rate  of  "  one-eighth  of  1  miner's  inch  of 
perpetual  flow  from  April  15  to  November  15  of  each  year  for  each  acre.'* 
This  is  equivalent  to  46,224  cubic  feet  per  acre  per  annum,  or  a  mean  depth 
of  12f  inches  over  the  land.  The  water-rate  of  12  per  acre  would  thus  be 
equal  to  4.3  cents  per  1000  cubic  feet,  or  0.57  cent  per  1000  gallons. 

The  altitude  of  Hemet  Valley  where  the  dam  is  located  is  approximately 
4300  feet.  The  watershed  area,  as  determined  from  the  topographic  map 
of  the  United  States  Geological  Survey,  is  69.5  square  miles,  the  extreme 
elevation  of  which  is  about  9000  feet.  This  point  is  Tahquitz  Peak,  a  spur 
of  Mt.  San  Jacinto.  The  total  drainage-area  of  the  San  Jacinto  Eiver 
above  the  mouth  of  the  canyon  is  141.8  square  miles.  The  reservoir  there- 
fore receives  the  run-off  from  nearly  one-half  the  entire  drainage-basin  of 
the  river.  The  average  yield  of  the  shed  has  not  been  accurately  deter- 
mined, although  it  has  been  insufficient  to  fill  the  reservoir  in  any  one 
season  since  1895.  The  irrigation  season  of  1899  began  with  but  1000 
acre-feet  in  the  reservoir  (gage  73  feet). 

The  present  capacity  of  the  reservoir  is  10,500  acre-feet,  but  the  addi- 
tion of  27^  feet  to  the  height  of  the  dam  will  increase  it  2^  times.  The 
cost  of  the  dam  and  irrigation-works  has  never  been  made  public.  The 
area  of  the  tract  depending  upon  the  reservoir  for  irrigation  is  about  7000 
acres,  of  which  not  more  than  half  have  been  irrigated. 

The  Bear  Valley  Dam,  California. — Probably  the  most  widely  known 
irrigation  system  in  California  is  that  of  the  Bear  Valley  Irrigation  Com- 
pany of  Redlands,  California,  chiefly  by  reason  of  the  remarkably  slender 
proportions  of  the  Bear  Valley  dam,  which  has  been  to  the  engineering 


U'A         IIKSEHVOIRS  FOR  IltKIGATlON,   WATKUrOWER,  ETC. 

ft';iteriiity  the  "  eighth  wonder  of  the  world,"  and  has  no  parallel  on  the 
globe.  The  dam  has  no  stability  to  resist  water-j^ressure  except  that  due 
to  its  arched  form,  and  it  has  been  expected  to  yield  at  any  time,  although 
it  has  successfully  withstood  the  pressure  against  it  for  fifteen  years,  and  is 
apparently  as  stable  as  it  ever  was.  The  probabilities  are  that  nothing  but 
an  extraordinary  flood,  or  earthquake,  or  a  combination  of  unusual  move- 
ments, will  ever  accomplish  its  destruction.  Such  vast  interests  are  now 
dependent  upon  the  water  stored  by  the  dam  that  its  failure  would  be  a 
public  calamity,  greatly  to  be  deplored.  The  settlements  of  Rediands, 
Crafton,  and  Highlands,  which  are  among  the  choicest  of  the  orange- 
growing  regions  of  southern  California,  and  the  irrigation  districts  of 
Alessandro  and  Perris,  are  the  outgrowth  of  this  water-storage,  although 
the  Perris  district  receives  but  a  small  portion  of  its  supply  from  this 
source.  Prior  to  the  construction  of  the  dam  in  1883-84,  the  natural 
streams  entering  the  San  Bernardino  Valley  had  been  entirely  appropriated 
and  used  in  irrigation,  and  had  apparently  reached  the  limit  of  their 
irrigable  duty.  No  storage-reservoirs  were  then  in  service,  and  the  creation 
of  the  Bear  Valley  reservoir  for  conserving  the  flood-waters  of  the  Santa 
Ana  River  has  more  than  doubled  the  area  of  land  irrigated  previous  to  its 
construction  in  the  territory  covered  by  its  water,  and  has  increased  the 
valuation  of  property  in  far  greater  ratio  The  useful  function  of  the 
storage-reservoir  was  never  more  fully  exemplified  than  in  this  case.  The 
Bear  Valley  dam  was  designed  and  built  by  F.  E.  Brown,  C.E.,  a  graduate 
of  Yale  Scientific  School.  The  construction  of  the  dam  was  a  bold  and 
difficult  undertaking,  as  it  was  the  pioneer  enterprise  of  California  for 
irrigation-storage,  and  the  site  is  in  a  remote  locality,  to  which  the  cement, 
tools,  and  supplies  had  to  be  hauled  over  a  rough  mountain-range  from 
San  Bernardino,  descending  on,  the  opposite  side  to  the  Mojave  Desert 
and  again  climbing  the  mountain  to  Bear  Valley,  a  total  distance  of  70 
miles.  The  cost  of  hauling  cement  was  110  per  barrel,  and  its  total  cost 
delivered  was  114  to  115  per  barrel  Under  such  conditions,  and  with  a 
scarcity  of  funds  for  what  was  considered  a  questionable  experiment,  it  is 
not  sarprising  that  economy  of  masonry  was  practiced  to  such  an  extent 
that  it  is  quite  without  a  parallel  for  boldness  of  design.  The  d&m  is 
curved  up-stream  with  a  radius  of  335  feet,  and  is  64  feet  high  from  base 
to  crest.  The  length  on  top  is  about  300  feet,  and  the  thickness  but  2.5 
to  3  feet  on  top,  and  8.5  feet  at  a  point  48  feet  below  the  crest,  where  it 
rests  on  a  base  of  masonry  that  is  13  feet  wide,  making  an  offset  of  about 
2  feet  on  each  side  at  the  center;  but  as  the  base  was  built  with  a  curve  of 
shorter  radius  than  the  upper  48  feet  of  the  dam,  the  offset  is  not  uniform, 
but  tapers  to  nothing  on  the  waterside  at  the  ends  of  the  base,  and  is  fully 
4  feet  wide  on  the  back.  The  lowest  foundation  of  the  base  is  20  feet  wide, 
as  shown  in  Figs.  77  and  78.    The  entire  dam  contains  about  3400  cubic 


Fig.  76a.— Lake  Hemet  (Cal  )  Masonry  Dam. 


f 


J 


MASONRY  DAMS. 


165 


yards  of  masonry,  in  which  were  used  about  1600  barrels  of  cement.  It  is 
reported  to  have  cost  175,000,  or  over  122  per  cubic  yard,  of  which  the 
cement  alone  cost  but  17.50  for  each  cubic  yard  of  masonry  laid.  That  the 
plant  and  labor  could  have  cost  so  much  as  $14.50  per  cubic  yard,  which  is 
several  times  the  ordinary  cost  of  such  work,  must,  if  true,  have  been 
largely  attributable  to  the  lack  of  adequate  machinery,  as  well  as  extrava- 
gant management.    The  masonry  is  a  rough,  uncut,  granite  ashlar,  with  a 


Fig.  77.— Cross-section  of  Bear  Valley  Dam. 


Fig.  78.— Plan  and  Elevation  of  Bear  Valley  Dam. 


hearting  of  rough  rubble,  all  laid  in  cement  mortar  and  gravel.  At  the 
beginning  an  earth  dam  was  erected,  2^  miles  above,  6  feet  in  height,  to 
retain  the  summer  flow.  As  the  masonry  rose  water  was  let  down  to  the 
main  dam,  forming  a  pond  which  floated  timber  rafts  on  which  stone  was 
transported  to  the  site,  and  from  which  construction  was  carried  on.  Hand- 
derricks  were  carried  on  these  rafts. 

The  work  was  evidently  done  slowly  and  with  great  care,  as  it  has  leaked 
but  little  beyond  the  usual  sweating,  which  has  left  its  marks  in  an  efflores- 
cence or  deposit  of  lime,  brought  out  of  the  mortar  by  the  moisture  oozing 
through.    This  occurred  during  the  first  few  years  after  completion  and 


!(')(>         RESEJiVOIJlS  FOR  IIUUGATION,  WATEU-POWEH,  ETC. 

lias  ulnioyt  entirely  ceased.  When  inspected  by  the  writer  in  August,  1896, 
the  water  stood  within  10  feet  of  the  top  of  the  darn  with  little  or  no  visible 
leakui^-e  below. 

^Plie  soath  end  of  the  dam  abuts  against  a  projecting  ledge  of  granite, 
standing  boldly  out  from  the  side  of  the  canyon  100  feet  or  more  beyond 
the  gen°eral  line  of  the  side  slopes,  illustrated  in  the  photograph,  Fig.  79. 
Over  the  top  of  this  ledge,  as  far  from  the  dam  as  it  could  be  placed,  a 
.spillway,  20  feet  wide,  was  excavated  to  a  depth  of  8.5  feet  below  the  level 
of  the  extreme  top  of  the  dam  (Fig.  80). 

The  extreme  capacity  of  this  spillv/ay  does  not  exceed  1700  second-feet, 
which  is  dangerously  small. 

The  great  Sweetwater  flood  of  1895  gave  a  maximum  discharge  of  nearly 
100  second-feet  per  square  mile  of  watershed.  A  freshet  of  proportional 
volume  from  the  Bear  Valley  shed  would  give  a  discharge  of  about  5600 
second-feet,  or  more  than  three  times  the  spillway  capacity.  Occurring  at 
a  time  when  the  reservoir  were  full,  such  a  flood  would  overtop  the  dam  by 
a  depth  of  2  to  3  feet.    The  result  might  be  disastrous. 

The  spillway  was  for  a  time  closed  with  sand-bags  to  hold  the  lake  to  a 
higher  level,  but  this  device  was  substituted  by  movable  flashboards, 
arranged  in  four  bays,  separated  by  suitable  framework. 

The  only  outlet  or  means  of  control  of  the  reservoir  is  an  iron  gate  made 
to  slide  on  brass  bearings,  and  closing  a  rectangular  opening,  20  by  24 
inches,  leading  to  a  culvert  cut  in  the  bed-rock.  The  culvert  trench  was 
made  2  feet  wide  and  3  feet  high,  flat  on  bottom  and  arched  over  the  top 
with  concrete.  The  dam  was  built  over  it,  and  the  culvert  simply  passed 
through  or  under  the  wall.  The  gate  is  operated  by  a  screw-stem  that 
passes  up  through  a  6-inch  pipe,  standing  vertically  in  the  water  next  to 
the  dam,  and  reaching  up  to  a  wooden  platform  at  the  coping-line.  The 
gate-stem,  hand-wheel,  and  mouth  of  outlet  culvert  are  shown  in  the  illus- 
tration. The  maximum  discharge  capacity  of  the  gate  when  wide  open 
with  full  reservoir  is  about  167  second-feet,  which  is  much  more  than  is 
ever  required  to  be  drawn.  The  capacity  with  reservoir  practically  empty 
is  over  80  second-feet. 

The  top  of  the  dam  is  not  finished  to  a  true  level  line,  as  the  coping- 
stones  have  been  omitted  over  about  one-half  the  length,  and  this  portion  is 
2  to  3  feet  lower  than  the  finished  crest.  It  requires  considerable  nerve  to 
walk  over  the  top  of  the  dam,  because  it  has  no  hand-rail  or  parapet  and  is 
:so  narrow  that  few  visitors  care  to  attempt  the  feat.  Water  has  stood  for  a 
■considerable  time  within  a  few  inches  of  overflowing,  although  it  has  never 
actually  passed  over  the  top,  as  the  spillway  has  thus  far  been  capable  of 
carrying  the  surplus  flood-water.  The  maximum  volume  stored  in  the 
reservoir  thus  far,  has  been  somewhat  in  excess  of  40,000  acre-feet,  and 


o^  m 
UNlVERSirVoflLUNOlt 


trnw^-ftsi^  v  of  iiUNOlt 


MASONRY  DAMS.  I73 

in  seasons  of  excessive  precipitation  the  run-off  has  exceeded  the  reservoir 
capacity. 

In  order  to  be  able  to  impound  the  entire  ran-off  from  the  watershed, 
or  the  greater  portion  of  it,  the  company  at  one  time  contemplated  the 
erection  of  a  higher  dam,  to  be  built  about  200  feet  down-stream  from  the 
present  dam,  and  impound  water  to  the  75-foot  contour  of  the  reservoir,  or 
11  feet  higher  than  the  crest  of  the  existing  structure,  at  which  level  the 
capacity  of  the  basin  is  80,000  acre-feet,  flooding  a  surface  area  of  3060 
acres  to  a  mean  depth  of  25.3  feet.    It  was  regarded  as  impracticable  to 
add  another  foot  to  the  height  of  the  present  dam,  and  no  engineer  cared 
to  risk  the  responsibility  of  excavating  at  the  toe  of  the  wall  for  such  an 
addition  to  it  as  would  enable  it  to  be  raised  to  the  desired  height;  hence 
it  was  deemed  best  to  go  a  safe  distance  below  to  avoid  jarring  or  disturb- 
ing the  fragile  wall,  and  there  begin  an  entirely  independent  structure. 
The  new  dam  was  designed  as  a  rock-fill,  and  was  to  be  80  feet  in  height 
above  the  base  of  the  present  dam,  but  was  never  finished  beyond  the 
foundations,  which  were  laid  in  a  substantial  manner  in  1893  (Fig.  81). 
It  is  a  matter  of  regret  that  the  second  dam  was  not  completed,  as  its  com- 
pletion was  recognizel  as  affording  a  rare  opportunity  for  studying  the  arch 
action  upon  the  present  ma.sonry  wall.    At  the  time  it  was  begun  a  com- 
mittee was  appointed  by  the  American  Society  of  Civil  Engineers  to 
examine  and  measure  the  movement  in  the  masonry  incident  to  the  loadino- 
and  unloading  of  the  arcli.     This  could  be  quickly  accomplished  by  empty°- 
mg  and  refilling  the  pond  between, tiie  twp.  dams.    If  taken  at  the  right 
time,  the  effect  of  a  flood  pouring  over  the  crest  ol  the  thin  masonry  wall 
could  have  been  observed,  and  much  useful  knowledge  obtaiiitd  on  the 
subject  of  the  strains  in  arched  dams  of  which  so  little  is  now  known. 

The  watershed  tributary  to  the  Bear  A^alley  reservoir,  as  determined 
from  the  best  available  maps,  is  approximately  56  square  miles,  the  maxi- 
mum elevation  of  which  is  about  7700  feet,  or  1500  feet  higher  than  the 
valley.  On  the  north  and  east  the  shed  borders  on  the  desert,  and  the  pre- 
cipitation shades  off  to  a  considerably  less  amount  than  is  recorded  at  the 
dam. 

The  record  of  rain  and  melted  snow  at  the  dam  from  1883  to  1893,  the 
season  beginning  in  each  year  on  September  1st,  is  as  follows: 

Inches.  Inches. 

1883-  81   94.60  1888-89   46.03 

1884-  85   28.06  1890-91   78.40 

1885-  86   65.51  1891-92..   ...      38  00 

188^^-87   24.00  1892-93   44.32 

1887-88   62.30  1894-95   50.00 


Mean  for  12  years  53.70 


lT-1         liESERVOlRS  FOR  nUtW ATION,  WATFIt-rOWKU,  ETC. 

The  dry  years  whieli  have  ocuarred  since  1895  must  midonbtedly  reduce 
this  mean  very  considerably,  although  the  record  lius  not  been  made  public. 
In  1891  the  run-oft'  from  the  watershed  was  computed  by  Wm.  I  Lam.  JIall 
from  the  records  of  catchment,  as  follows,  beginning  with  the  completion 
of  the  dam: 

Run-off.  Q       .  Iluii-off. 

Season.  Acre-feet.  Acre-feet. 

1883-  84   230,000  1887-88   132,400 

1884-  85   21,000  1888-89   70,400 

1885-  80   142,400  1889-90   211,000 

1880-87   8,000  1890-91..,   180,800 


Mean  120,150 

This  estimate  is  so  large  as  to  be  decidedly  questionable.  Mr.  J.  B. 
Lippincott,  Hydrographer  "CT.  S.  Geological  Survey,*  estimates,  by  compari- 
son of  observations  in  other  parts  of  the  State,  that  the  probable  maximum 
run-oft  of  the  shed  is  about  100,000  acre-feet,  and  the  mean  about  28,500. 
The  minimum  was  doubtless  reached  in  1895-99.  The  irrigation  season  of 
1899  began  with  but  1500  acre-feet  in  the  reservoir,  a  small  portion  of 
which  was  held  over  from  the  previous  year.  This  was  entirely  exhausted 
early  in  the  season,  and  an  attempt  was  made  to  maintain  the  supply  by 
pumping  from  shallow  wells  in  the  bed  of  the  reservoir,  although  with 
indifterent  success.  Four  to  six  acre-feet  per  day  were  obtained  for  a  time, 
but  it  was  largely  dissipated  by  evaporation  in  passing  down  the  canyon. 

The  loss  to  be  anticipated  from  this  reservoir  by  evaporation  is  a  sub- 
ject of  much  interest.  It  is  at  an  altitude  of  0200  feet,  and  well  sheltered 
from  winds  by  surrounding  mountains,  favoring  minimum  loss.  On  the 
other  hand  the  v/ater  is  shallow  and  spread  out  over  a  large  area.  Observa- 
tions made  at  the  gate-house  of  the  Arrowhead  Reservoir  Company  in  Little 
Bear  Valley,  in  the  same  mountain-range,  but  at  lower  elevation  (5100  feet 
above  sea-level),  indicate  that  the  evaporation  from  water-surface  is  about 
30  inches  per  annum  in  that  locality,  of  which  about  90^  occurs  in  the 
eight  months  from  March  to  November,  inclusive.  This  rate  of  loss  applied 
to  Bear  Valley  reservoir  when  full  would  indicate  a  probable  loss  of  over 
20^  per  annum  if  no  water  were  drawn  out,  or  about  14^  per  annum  if  a 
uniform  draft  of  2500  acre-feet  per  month  were  made  during  the  period 
from  March  to  November,  inclusive. 

The  general  form  of  the  reservoir  is  shown  in  Fig.  82. 

La  Grange  Dam,  California. — There  is  something  quite  unusual  in  a 
masonry  dam  125  feet  high  which  is  erected  for  the  sole  purpose  of  divert- 
ing water  from  a  stream  for  irrigation  purposes,  and  this  is  the  character  of 
structure  that  was  built  on  the  Tuolumne  River,  \\  miles  above  the  town 


*  Nineteenth  Annual  Report  for  1897,  U.  S.  Geol.  Sur.,  Part  IV.,  p.  585. 


MASONRY  DAMS. 


17a 


176         BESERVOinS  FOR  IRRIGATION,  WATEH-POWEH,  ETC. 


of  La  Gruuge,  California,  in  1891-94,  by  the  Turlock  and  Modesto  irriga- 
tion districts  jointly.  The  'J'uolumne  River,  as  it  leaves  the  mountains,  on 
its  way  across  the  San  Joaquin  Valley,  is  cut  down  so  deeply  below  the 
geneial  level  of  tlie  2)lain  as  to  require  a  higli  dam  to  raise  the  water  suffi- 
ciently to  get  it  out  on  the  irrigable  lands.  The  dam  is  located  at  the 
mouth  of  a  narrow  box  canyon  and  is  in  no  sense  designed  or  used  for 
storage.  It  is  125  feet  high  on  the  up-stream  face,  129  feet  on  the  down- 
stream side,  90  feet  in  thickness  at  bottom,  24  feet  at  crest,  and  but  310 
feet  long  on  top.  The  wall  is  built  as  the  segment  of  a  circle  of  300  feet 
radius,  the  arch  being  opposed  to  the  direction  of  the  water-pressure, 
although  its  profile  is  of  purely  gravity  type,  in  which  the  lines  of  pressure 
are  well  within  the  middle  third.  On  the  water-face  the  dam  is  vertical  for 
70  feet  below  the  top,  and  thence  to  the  foundation  has  a  batter  of  1  in  20. 
The  edges  of  the  crest  are  rounded  off  on  a  radius  of  3  feet  on  upper  side, 
and  17.5  feet  on  lower  side,  leaving  6  feet  of  the  crest  level.  At  6  feet 
below  the  crest  the  dam  is  24.13  feet  thick;  at  69  feet  below  it  is  52  feet 
thick;  at  89  feet  it  is  66.25  feet;  and  at  97  feet,  the  top  of  the  foundation 
masonry,  it  is  84  feet  thick.  The  extreme  bottom  width  at  the  highest 
point  of  the  dam  is  90  feet.  The  lower  face  has  a  batter  of  -|-  to  1,  from  70 
feet  below  the  crest.  *vhere  a  compound  curve  of  63  and  23  feet  radii 
commences,  which  carries  the  face  to  its  intersection  with  the  battered  face 
of  the  foundation  masonry  about  3  feet  above  low  water.  From  this  point 
the  foundation  batter  is  1  in  7,  to  the  bottom,  about  32  feet  in  the' 
deepest  place.  These  dimensions  give  practically  an  ogee  form  to  the 
down-stream  face,  which  permits  the  water  to  follow  the  masonry  without 
leaving  its  face  in  its  descent,  provided  the  depth  be  not  more  than  4  to  5 
feet,  and  gives  it  a  horizontal  direction  at  the  bottom.  The  curvature  of 
the  dam  and  the  fact  that  the  canyon  is  but  80  feet  wide  at  the  base  of  the 
dam,  or  top  of  foundations,  so  concentrate  the  stream  that  some  erosion 
may  be  anticipated  at  the  base,  although  nothing  serious  in  that  line  has 
been  reported. 

The  dam  contains  39,500  cubic  yards  of  masonry  and  cost  1550,009. 
It  is  built  throughout  of  rough,  uncoursed  rubble  masonry,  laid  in  Portland- 
cement  concrete,  in  practically  the  same  manner  as  that  described  in  the 
construction  of  the  Hemet  dam.  The  work  was  done  by  contract,  at  $10.39 
per  cubic  yard,  including  the  excavation  for  foundations,  but  not  including 
cement,  which  was  furnished  by  the  districts.  The  cement  cost  $4.50  per 
barrel  delivered,  and  31,500  barrels  were  used  in  the  work. 

It  is  believed  to  be  the  highest  overflow  dam  in  the  United  States,  if  not 
in  the  world.  The  volume  of  water  passing  over  it  may  in  extreme  floods 
amount  to  100,000  second-feet.  The  maximum  flood  that  has  yet  gone 
over  the  dam  was  about  46,000  second-feet  in  volume,  the  depth  on  crest 
being  12  feet. 


Fig.  82«.— Plan  of  La  GRANGr  Dam,  California, 


Fig  82&. — Profile  of  La  Grange  Dam,  California. 

177 


178         BESERVOim  FOR  IRltlQATlON,  WATER-POWER,  ETC. 


During  construction  the  low-wtiter  (liy(;hargG  was  carried  past  the  work 
in  a  flume  tlie  first  year,  and  subsequently  tlirougli  two  culverts,  one  at  low- 
water  level,  and  a  second  10  feet  higher.  These  were  4  feet  wide,  6  feet 
high. 

The  Modesto  Canal  takes  water  through  an  open  cut  from  the  dam,  on 
the  right  bank,  and  has  a  capacity  of  750  second-feet.  The  Turlock  Canal 
reaches  the  reservoir  above  the  dam  by  means  of  a  tunnel  560  feet  long,  12 
feet  wide,  11  feet  high,  with  regulating-gate  at  the  head. 


Fig.  83.— Upper  Face  of  La  Grange  Dam. 


In  construction  of  the  dam  three  hues  of  cableway  were  used,  spanning 
the  canyon,  for  hauling  the  materials. 

The  excessive  cost  of  the  work  was  doubtless  due  to  the  uncertainty  as 
to  the  value  of  the  bonds  of  the  irrigation  districts,  which  created  a  temerity 
among  contractors,  and  there  were  few  bidders.  The  contractor  was 
obliged  to  buy  the  bonds  at  not  less  than  90^  of  their  face  value,  and  dispose 
of  them  at  a  figure  from  which  he  could  obtain  a  profit  on  his  work. 
Under  ordinary  conditions  of  prompt  payments  in  cash  the  construction 
should  have  been  done  for  one-half  the  actual  cost. 

The  dam  was  designed   by  Luther  Wagoner,  C.E.,  who  resigned 


MASONRY  DAMS. 


179 


shortly  after  work  began,  and  construction  was  completed  under  charge  of 
E.  H.  Barton,  engineer  for  the  Turlock  district,  and  H.  S.  Crowe,  repre- 
;senting  the  Modesto  district. 

The  elevation  of  the  crest  of  the  dam  is  299.3  feet  above  sea-level,  and 
the  canal  grade  is  8.3  feet  lower. 

The  Turlock  irrigation  district  embraces  176,210  acres,  and  the  canal 
supplying  it  has  a  reported  capacity  of  1500  second-feet.  The  main  canal 
is  18  miles  long,  feeding  five  laterals  of  an  aggregate  length  of  80  miles. 


Fig.  84.— Lower  Face  of  La  Gt^akhf,  dam. 


The  Modesto  district  covers  81,500  acres,  witli  a  main  canal  22.75  miles 
long  before  reaching  the  district,  having  a  capacity  of  640  second-feet. 
The  entire  irrigation  system  when  fully  completed  will  be  the  largest  and 
most  comprehensive  one  in  California,  and  tbe  dam  upon  which  its  success 
depends  has  been  wisely  constructed  of  such  dimensions  as  to  be  of  unques- 
tionable stability.    Figs.  83  and  84  give  two  views  of  the  structure. 

Folsom  Dam,  California.— There  are  many  features  of  the  Folsom  dam, 
on  the  American  River,  California,  which  give  it  special  interest  to  engi- 
neers and  all  others  who  have  seen  it,  one  of  which  is  tbat  it  was  built  by. 
the  State  of  California  entirely  with  convict  labor,  incidentally  to  give 
•employment  to  the  inmates  of  one  of  the  State  prisons,  but  primarily  to 


180         UESIUiVOlliS  FOR  llililGATION,  WA7 EJi-PO  \VEh\  EIC. 


develop  water-power  for  use  in  various  industries  about  the  prison  and  i'or 
transmission  to  other  localities.  A  further  pnrpose  is  served  by  the  dam  in 
the  diversion  of  water  from  the  American  liiver  out  ui)on  the  plains  of  the 
Sacramento  Valley  for  irrigation.  The  plan,  profile,  and  section  of  the 
dam  are  shown  in  Eig.  90,  and  a  photograph  taken  by  a  convict  during; 
construction  is  given  in  Fig.  91. 

The  dam  is  of  the  same  general  character  as  the  La  Grange  dam, 
serving  no  purpose  of  storage,  but  designed  solely  for  the  diversion  of  the 
stream  and  so  constructed  as  to  permit  flood-water  to  pass  freely  over 
its  crest. 

It  is  located  at  the  top  of  a  natural  fall  in  the  bed-rock  of  the  stream^ 
its  height  at  the  up-stream  toe  being  69.5  feet,  while  at  the  down-scream 
footing  the  height  is  98  feet  to  the  crest-line.  The  top  thickness  is  24 
feet;  base  87  feet.  A  movable  shutter,  180  feet  long,  is  placed  in  the  center 
of  the  dam  for  raising  the  normal  water-level  at  low  stages.  This  shutter 
is  placed  in  a  depression,  6  feet  in  depth,  below  the  general  level  of  the  dam, 
and  is  lowered  during  floods  to  allow  the  passage  of  extreme  freshets  over 
the  dam.  '  At  low  water  the  shutter  is  raised  to  a  nearly  vertical  position 
by  means  of  liydraulic  jacks,  as  shown  in  Fig.  92,  which  are  operated  from 
the  prison  power-house.  The  entire  cre&t  length  of  the  dam  is  650  feet, 
including  the  curved  approach  to  the  canal  head-gates. 

The  main  dam  is  straight  in  plan.  The  construction  of  the  dam  was 
begun  in  1886  and  completed  in  1891.  It  contains  48,590  cubic  yards  of 
masonry  in  the  dam  proper,  while  the  retaining-wall  of  the  canal  has 
27,000  cubic  yards  and  the  power-house  13,700  cubic  yards  of  granite 
masonry,  all  laid  in  Portland-cement  mortar.  The  dam  is  a  very  massive 
and  substantial  piece  of  masonry,  composed  of  rough  granite  ashlar  in 
large  blocks  of  10  tons  or  more  in  weight.  The  quarry,  which  deter- 
mined the  location  of  the  State  prison,  affords  an  unlimited  quantity  of  excel- 
lent granite  which  has  a  fine  cleavage  and  is  readily  quarried  into  blocks  of 
any  desired  size.  The  excavation  of  the  canal  along  the  granite  cliff  gave  all 
the  material  needed  for  the  dam.  The  stone  was  delivered  to  the  dam  by  a 
cablevvay  of  unusual  construction,  in  that  two  cables  were  used  side  by  side 
like  a  suspended  rail  way- track,  and  the  trolley  was  a  four-wheeled  carriage 
from  which  the  loads  were  hoisted  and  suspended.  There  are  many  disad- 
vantages to  this  form  of  cableway,  and  no  special  features  to  recommend  it 
as  preferable  to  the  single  cable.  The  latter  admits  of  dragging  rocks  from 
either  side  of  the  line  of  the  cable  for  a  considerable  distance,  an  operation 
which  would  tend  to  derail  the  trolley  of  a  double  cableway. 

The  canal  taken  from  the  left  side  of  the  dam  passes  through  the 
prison  grounds  and  thence  to  the  town  of  Folsom,  one  and  one-half  miles 
below,  where  the  main  power-drop  of  85  feet  is  utilized  for  generation  of 
power,  which  is  transmitted  electrically  to  Sacramento,  22  miles  distant. 


TEE  Crest. 


181 


Fig.  87.— La  Grange  Dam,  California. 


0^  THE 
UNIVERSITY  .^fiLUNOU 


•Map  showing  Location  of  Folsom  Dam  and  the  Main  Canal. 


MASONRY  DAMS. 


189 


In  passing  the  prison  power-house  a  drop  of  7.5  feet  is  utilized  by  six 
87-inch  Leffel  turbines  of  the  double  improved  type,  and  about  800  H.P. 
are  developed  at  the  maximum.  The  canal  is  8  feet  in  depth  throughout, 
the  width  below  the  prison  power-house  being  30  feet  on  bottom,  40  feet 
on  top.  Above  the  power-house  the  width  is  10  feet  greater.  The  grade 
is  1 : 2000,  and  the  capacity  of  the  canal  about  1000  second-feet. 


Fig.  92.— Kydraultc  Jacks  for  raising  Sputter  on  Folsom  Dam. 


The  San  Mateo  Dam,  California.— Doubtless  the  most  enormous  mass  of 
masonry  of  any  sort  in  the  West,  if  not  in  the  entire  United  States,  is  the 
great  concrete  dam  erected  on  San  Mateo  Creek,  6  miles  above  the  village 
of  San  Mateo,  California,  by  the  Spring  Valley  Water-works  of  San  Fran- 
cisco, to  impound  water  for  the  supply  of  that  city.  The  dam  ranks 
among  the  highest  and  most  costly  of  the  world,  and  was  erected  in  1887 
and  1888. 

It  was  projected  to  reach  to  a  height  of  170  feet,  at  which  the  top  width 
was  to  be  25  feet  and  base  width  176  feet,  but  construction  was  suspended 
at  the  height  of  146  feet,  or  34  feet  below  the  ultimate  height.  When 
finished  the  top  length  will  be  680  feet.  It  has  a  uniform  batter  of  4  to  1 
on  the  up-stream  face,  while  the  lower  slope,  beginning  with  a  batter  of  2^ 
on  1  near  the  top,  curves  with  a  radius  of  258  feet  to  near  the  bottom, 
wliere  the  batter  is  1  to  1.  The  dam  is  arched  up-stream  with  a  radius  of 
637  feet. 

It  is  built  throughout  with  concrete,  made  of  broken  stone,  beach  sand, 
and  Portland  cement.  This  material  was  chosen  because  of  the  difficulty  of 
securing  rock  in  the  vicinity  suitable  for  rubble  masonry.  The  stone  was 
quarried  in  the  immediate  vicinity,  and  occurred  in  small  irregular  nodules. 


1<)()         lihJSEIiVOJIiti  FOR  IIUiJOATlON,  WATER-POWER,  ETC. 

frequently  so  coated  with  clay  and  serpentine  as  to  require  it  to  be  thoroughly 
washed  before  it  was  fit  for  use.  After  crushing,  it  was  passed  through 
revolving  cylindrical  tumblers,  where  a  constant  stream  of  water  was  main- 
tained to  carry  off  the  mud  and  tailings,  which  passed  off  through  a  flume 
and  dropped  to  the  stream-channel,  where  the  deposit  from  these  washings 
covered  several  acres  to  a  considerable  depth.  The  proportion  of  waste  was 
large.  The  sand  used  in  the  concrete  was  obtained  from  the  sand-dunes  of 
North  Beach,  San  Francisco,  where  it  was  loaded  on  cars,  hauled  one  mile, 
and  dumped  into  barges,  then  towed  25  miles  up  the  bay  to  a  landing  oppo- 
site San  Mateo,  and  thence  hauled  6  miles  by  wagon  to  the  dam.  All  the 
materials  were  thus  unusually  expensive. 

The  concrete  was  mixed  in  a  battery  of  6  cubical  iron  mixing-machines 
revolved  by  steam-power.  It  was  delivered  to  the  work  by  a  double-track 
tramway  on  a  high  trestle  carried  part  way  across  the  canyon  at  the  level  of 
the  top  of  the  dam  on  the  lower  side,  as  shown  in  Fig.  94.  The  cars  on  this 
tramway  were  pushed  by  hand  and  dumped  into  hoppers  let  into  the  floor 
between  the  rails,  leading  to  vertical  pipes,  16  inches  in  diameter,  which 
extended  down  to  platforms  that  were  placed  from  time  to  time  at  a  level 
with  the  top  of  the  work  as  as  it  progressed.  The  concrete  dropped  down 
these  pipes,  striking  on  steel  plates,  from  which  it  was  shoveled  into  wheel- 
barrows and  trundled  to  the  place  of  use.  The  height  of  this  drop  was 
sometimes  as  great  as  120  feet,  but  no  injury  resulted  to  the  concrete,  or  to 
the  men  shoveling  it  as  it  fell.  The  concrete  was  mixed  in  the  proportions 
of  1  part  cement  to  2  parts  sand,  6i  parts  broken  stone,  and  f  part  water 
by  measure.  It  was  moulded  in  cyclopean  blocks  of  200  to  300  cubic  yards 
each,  with  numerous  offsets  ingeniously  dovetailing  the  blocks  together,  and 
every  possible  precaution  was  taken  in  the  joining  of  the  successive  portions 
to  secure  an  absolute  bond.  The  surfaces  of  the  blocks  after  the  forms  were 
removed  were  roughened  with  picks,  swept  and  washed  clean,  and  grouted 
with  pure  cement  before  concrete  was  placed  against  them.  The  result  has 
been  very  satisfactory;  the  dam  is  almost  absolutely  water-tight,  although 
some  moisture  does  find  its  way  through  and  appears  in  spots  on  the  lower 
face.  No  settlement  or  expansion  cracks  are  visible,  and  the  work  has  the 
appearance  of  being  absolutely  homogeneous.  Figs.  96  and  97  show  the 
general  method  of  forming  the  blocks  and  preparing  them  to  receive  fresh 
concrete,  and  Fig.  98  is  a  general  view  of  the  dam  taken  at  the  time  of  the 
visit  of  the  American  Society  of  Civil  Engineers  in  Annual  Convention, 
July,  1896.  Plans  and  sections  of  this  dam  are  shown  in  Fig.  99.  At  the 
170-foot  level  the  reservoir  will  have  a  capacity  of  29,000,000,000  gallons, 
or  89,000  acre-feet.  The  present  capacity  is  approximately  20,000,000,000 
gallons. 

The  entire  volume  of  the  dam  is  approximately  139,000  cubic  yards. 
When  the  dam  is  extended  to  its  ultimate  height  it  will  be  necessary  to 


ijtV  THE 
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imm<y 


Fh).  1)9.— Plans  and  SiaTioNS  oF 


ON  THROUGH  GATETOWER  AND  OUTLET  TUNNEL 


TYSTAL  SPR/NGS  RESERVOIR 


ATEO  Dam  and  Map  of  Crystal  SpiiiNGB  Reservoir. 


Of-  THE 


MASONRY  BAMS. 


203 


close  a  gap  in  the  ridge  a  short  distance  north  with  a  wall  about  25  feet 
high.  The  outlet  to  the  dam  is  a  tunnel  390  feet  long,  driven  through  the 
hill  on  the  north  side  of  the  channel,  through  which  a  54-inch  riveted  iron 
pipe  is  laid.  The  tunnel  is  7^  feet  wide  inside  the  lining,  and  of  the  same 
height,  and  is  lined  with  four  courses  of  brick,  21  inches  thick. 

The  tunnel  is  intersected  by  a  brick-lined  shaft,  14  feet  clear  diameter, 
placed  just  inside  the  dam  in  the  reservoir.  Inside  this  shaft  is  a  stand-pipe 
connecting  with  the  main  outlet-pipe.  Three  branch  tunnels,  carrying  large 
pipes,  open  out  from  the  reservoir  to  this  stand-pipe,  each  pipe  being  con- 
trolled by  gate-valves  that  are  placed  in  the  main  shaft.  This  is  an  admir- 
able form  of  outlet,  as  all  the  pipes  from  the  shaft  are  accessible  to  inspection 
and  repair.  The  ends  of  the  tunnels  under  water  have  plain  cover-valves 
over  elbows,  and  are  provided  with  fish-screens  that  are  put  into  position 
from  floating  barges.  A  main  pipe,  44  inches  in  diameter,  leads  from  the 
dam  to  San  Francisco.  The  present  crest  of  the  dam  is  281  feet  above  tide- 
level. 

When  the  reservoir  is  filled  it  submerges  the  old  Crystal  Springs  reser- 
voir and  dam,  the  latter  being  an  earth  structure  which  did  service  for  many 
years  until  superseded  by  the  new  dam.  smaller  reservoir,  that  formerly 
supplied  the  town  of  San  Mateo,  was:.al§p  obliterated  from  view,  and  the 
water  at  highest  level  will  ex-tefldUip- tile* -^^ll^y^of  the  north  arm  of  the 
creek  nearly  to  the  toe  of  the  San  Andreas  dam. 

The  old  Crystal  Springs  reservoir  had  a  tributary  watershed  of  14  square 
miles,  which  yielded  a  mean  annual  run-off  of  319  acre-feet  per  square  mile 
during  the  eight  years  from  1878  to  1886.  The  mean  rainfall  during  that 
period  was  34.95  inches.  This  run-off  is  equivalent  to  a  mean  of  14.4^  of 
the  mean  rainfall,  the  maximum  having  been  34^  and  the  minimum  0.5^. 

The  Pilarcitos  and  San  Andreas  watersheds,  whose  catchment  is  retained 
by  earthen  dams,  receive  a  much  higher  precipitation,  especially  the  former, 
which  is  more  directly  exposed  to  the  saturated  wind-currents  from  the 
ocean.  The  average  precipitation  over  all  the  Spring  Valley  Water  Co.'s 
sheds,  during  the  seven  years  from  1868  to  1875,  was  43.5  inches,  from 
which  the  mean  run-off  was  35.5^,  including  loss  by  evaporation.  These 
watersheds  are  partially  wooded,  undulating  pasture-lands,  uncultivated, 
covered  with  deep  soil,  and  clothed  with  native  grasses  that  spring  up  annu- 
ally from  seed  and  have  little  permanent  sod.  The  results  of  the  measured 
catchment  from  these  areas  indicates  that,  in  general  terms,  on  watersheds 
of  this  character  from  20  to  35  inches  of  rainfall  are  annually  taken  into  the 
soil  and  absorbed  in  plant-growth  and  evaporation. 

The  Nevjell  Curve  of  Run-off. — On  Fig.  100  is  shown  a  diagram,  called 
the  ''Newell  Curve,"  from  its  originator,  Mr.  F.  H.  Newell,  C.E.,  Chief 
Hydrographer,  U.  S.  Geological  Survey,  which  expresses  the  general  relation 
between  mean  annual  rainfall  and  mean  run-off,  as  determined  from  the 


204        UESERVOlllti  FOli  lUlilGATlON,   WATEli-POWER,  ETC. 


MA80NRT  BAMS, 


205 


measurements  of  a  large  number  of  streams,  compared  with  the  best  avail- 
able data  as  to  the  probable  mean  precipitation  on  the  watersheds  of  those 
streams.  This  is  a  convenient  diagram  for  general  deductions,  as  it  shows 
at  a  glance  the  increasing  percentage  of  run-off  to  be  expected  from  heavy 
rains,  and  the  very  small  amount  to  be  derived  from  low  rainfall.  Upon 
this  diagram  the  author  has  platted  a  number  of  actual  measurements  of 
run-off  on  certain  California  watersheds  and  some  others,  which  are  mostly 
indicative  of  lower  percentage  of  run-off  than  the  lines  of  the  curve.  The 
difficulty  in  applying  such  a  diagram  to  estimates  of  probable  run-off  is  in 
determining  the  mean  rainfall  applicable  to  any  given  shed,  and  in  the 
variability  of  run-off  in  different  seasons,  due  to  the  uneven  manner  in 
which  storms  appear.  Eains  gently  and  evenly  distributed  will  give  a  much 
smaller  stream-flow  than  the  same  amount  would  yield  if  it  came  in  a  succes- 
sion of  violent  storms,  quickly  following  one  another. 

Pacoima  Submerged  Dam,  California.— One  of  the  most  novel  and  inter- 
esting masonry  dams  erected  for  impounding  water  in  California,  where  so 
many  novelties  and  experimental  works  have  been  carried  out,  is  a  slender 
little  reservoir  wall  built  across  Pacoima  Creek,  in  the  San  Fernando  Valley, 
20  miles  north  of  Los  Angeles,  for  the  purpose  of  forming  an  underground 
reservoir,  whose  storage  capacity  consists  solely  of  the  voids  in  the  gravel- 
bed  filling  the  valley  of  the  stream. 

The  creek  drains  a  watershed  whose  area  is  30.5  square  miles  above  the 
point  where  it  issues  from  the  mountains.  Here  it  flows  over  exposed  bed- 
rock, and  the  normal  summer  flow,  which  diminishes  gradually  from  about 
100  to  less  than  10  miner's  inches,  is  entirely  diverted  by  a  pipe-line  and 
used  below  for  irrigation.  The  dam  in  question  is  located  2|-  miles  further 
down,  where  the  channel  of  the  stream  is  contracted  to  a  width  of  550  feet 
by  a  ledge  of  sandstone  which  crosses  it  at  about  right  angles.  Between 
the  dam  and  the  mouth  of  the  canyon  is  a  continuous  bed  of  gravel,  in 
places  half  a  mile  wide,  which,  though  lying  on  a  heavy  grade,  constitutes 
the  storage-reservoir.  The  dam  was  constructed  by  excavating  a  straight 
trench  (shown  in  Fig.  101),  6  feet  wide,  from  side  to  side  of  the  channel, 
down  to  and  into  the  sandstone  bed-rock.  In  the  center  of  the  trench  a 
wall  of  rubble  masonry  was  laid,  3  feet  wide  at  base,  2  feet  at  surface,  using 
the  cobbles  excavated  from  the  trench,  and  a  mortar  of  Portland  cement 
and  sand.  The  mistake  was  made  of  not  filling  the  entire  width  of  the 
trench  with  concrete,  thoroughly  rammed  between  the  side  walls,  which 
would  probably  have  insured  satisfactory  water- tightness.  As  it  was,  the 
space  each  side  of  the  wall  was  refilled  with  gravel,  and  the  wall  was  not 
thick  enough  or  sufficiently  well  pointed  to  be  entirely  water-tight.  The 
general  height  of  the  wall  is  40  feet,  the  maximum  being  52  feet.  Plan, 
profile,  and  section  of  the  dam  are  shown  in  Fig.  103.    Two  gathering- 


206         IlESmiVOIllS  FOR  iniilOATION,  WATER-POWEU,  ETC. 


wells  arc  provided  iu  the  line  of  the  wall,  each  4  feet  inside  diameter, 
reaching-  from  boUoni  to  top. 

Three  lines  of  drain-pipes,  8  and  10  inches  diameter  and  made  of  asphalt 
concrete,  laid  with  open  joints,  are  ])laced  inside  the  dam  leading  to  the 
Avells,  the  fnnction  of  which  is  to  gather  the  water  and  feed  it  to  the  wells. 
Outlet-pipes  14  inches  diameter,  one  from  each  well,  lead  to  either  side  of 
the  valley.  These  are  placed  13  feet  below  the  top  of  dam  and  connect 
with  a  main  leading  to  the  pipe  distributing  system  supplying  the  irrigated 
lands.  When  the  reservoir  is  drained  down  to  the  level  of  these  outlets 
further  draft  is  made  by  pumping,  which  is  required  for  about  100  days 
during  late  summer  and  fall. 

The  cost  of  the  dam  is  given  at  $50,000,  and  the  volume  of  masonry 
was  about  2000  cubic  yards.  It  is  a  piece  of  amateur  work,  built  without 
engineering  advice,  but  it  serves  a  useful  purpose,  though  not  at  all  commen- 
surate to  its  cost.  It  is,  however,  a  type  of  dam  that  may  be  applicable  to 
other  localities  more  naturally  favorable  than  this. 

The  dimensions  and  capacity  of  this  novel  reservoir  cannot  be  clearly 
determined,  but  its  surface  area  is  approximately  300  acres,  its  mean  depth 
probably  15  to  20  feet,  and  its  capacity  equivalent  to  the  volume  of  voids  in 
the  gravel,  or  1300  to  1500  acre-feet. 

Agua  Fria  Dam,  Arizona.— One  of  the  tributaries  of  the  Gila  Eiver, 
which  joins  it  from  the  north,  below  the  city  of  Phoenix,  is  the  Agua  Fria 
Eiver,  heading  in  the  mountains  near  Prescott,  and  draining  some  1400 
square  miles  of  mountainous  territory.  The  Agua  Fria  Land  and  Water 
Company  have  erected  a  masonry  diverting-weir  across  the  stream,  at  a 
point  li  to  2  miles  above  the  northerly  line  of  Gila  Valley,  and  have  pro- 
jected a  storage-dam  li  miles  higher  up  the  stream,  at  a  point  called  the 
Frog  Tanks,  to  impound  the  flood-water  for  irrigation  of  the  plains, 
beginning  some  twenty  miles  west  of  Phoenix. 

The  dam  is  projected  to  the  height  of  120  feet  above  the  bed  of  the 
stream.  The  width  of  the  canyon  is  here  298  feet  at  the  level  of  the  sand, 
but  at  top  the  dam  will  be  1160  feet  long.  Sections  of  the  two  dam-sites 
and  profiles  of  the  dams  are  shown  in  Fig.  105.  Soundings  have  been 
made  over  the  greater  portion  of  the  channel  width,  and  what  is  presumed 
to  be  bed-rock  has  been  found  at  depths  of  9  to  15  feet,  but  for  a  space  of 
50  feet  no  bottom  was  found  with  24-foot  sounding-rods.  As  the  greatest 
depth  to  bed-rock  at  the  diverting-dam  below  was  but  40  feet,  this  depth  has 
been  assumed  for  the  maximum  of  the  unexplored  50  feet  at  the  upper  site, 
thus  making  the  extreme  height  of  the  dam  160  feet.  The  reservoir  to  be 
closed  by  this  dam  will  be  5  miles  in  length,  flooding  an  area  of  3200 
acres  and  impounding  108,000  acre-feet.  With  a  dam  of  gravity  profile, 
with  base  of  1 24  feet  and  crest  8  feet  wide,  the  volume  of  masonry  required 
is  computed  at  128,650  cubic  yards. 


Mm 


0>  THE 


MASONRY  DAMS. 


211 


The  enterprise,  when  completed,  is  expected  to  furnish  water  for  irrigat- 
ing 50^000  acres  of  superb  valley  land  that  is  now  an  absolute  desert.  A 
main  canal  has  been  projected,  25  miles  in  length,  with  a  capacity  of 
400  second-feet,  and  some  4  miles  of  the  heaviest  work  was  completed 


Plan 


Section  OF  Well 


'ock 

Section  OF  Wall 


Fig.  103. — Plan  and  Pkofile  of  Pacoima  Dam. 


from  the  dam  down  the  left  bank,  to  the  point  where  the  canal  is  intended 
to  cross  the  river  by  a  700-foot  flume.  This  canal  is  18  feet  on  bottom 
and  is  to  carry  8  feet  depth  of  water,  on  a  grade  of  2.11  feet  per  mile.  The 
diversion-dam,  upon  which  about  |100,000  had  been  expended  at  the  time 
work  was  suspended  in  the  fall  of  1895,  will  have  a  top  length  of  640  feet, 
a  maximum  height  of  80  feet,  a  top  width  of  10  feet,  and  a  base  of  65  feet. 


212         JlESimVOIllS  FOR  IimiGATlON,  WATER  POWER,  ETC. 


Wlicn  fniislied  it  will  contjiiii  17,200  cubic  yards  of  masonry,  and  will  have 
cost  in  the  neighborhood  of  $150,000. 

The  only  a])parent  purpose  of  this  dam  was  to  save  the  construction  of 
a  conduit,  1|-  miles  in  length,  in  the  canyon  between  the  storage-dam  proper 
and  the  diverting-weir.  The  storage-dam  must  be  built  before  the  scheme 
is  of  any  value,  or  before  there  is  any  water  available  for  irrigation. 

The  reasons  which  led  to  this  error  in  judgment  were,  first,  a  misappre- 
hension as  to  the  depth  to  bed-rock  at  the  lower  site.  In  fact,  the  dam  was 
begun  without  a  sufficient  knowledge  of  what  a  great  undertaking  it  was  to 
be,  and  so  much  money  had  been  expended  before  it  was  known  or  suspected 
that  the  extreme  depth  finally  reached  was  to  be  so  great  that  it  was  then 


Fig.  104.— Measuring- box  uskd  by  Maclay  Rancho  Water  Company. 
too  late  to  abandon  the  work.  The  second  reason  was  the  confident  expecta- 
tion that  the  volume  of  underflow  that  would  be  brought  to  the  surface  of 
the  dam  would  reach  from  "  500  to  1000  miner's  inches,''  which,  if  real- 
ized, would  have  enabled  the  projectors  to  use  the  canal  at  once  in  the  rec- 
lamation of  the  desert  land  entered  under  the  United  States  Desert  Land 
Act  before  the  main  reservoir  could  be  made  available.  This  underflow" 
development  was,  however,  a  sore  disappointment,  as  the  flow  when  finally 
secured  amounted  to  less  than  fifteen  miner's  inches,  about  what  had  been- 
predicted  by  the  writer  when  consulted  on  the  subject  a  year  or  more 


The  cross-sectional  area  of  the  two  channels  in  which  the  underflow  was 
passing  beneath  the  surface  is  approximately  as  follows : 


before. 


East  Channel 
West  " 


504  square  feet. 


2635 


Total   3139      "  " 

If  the  voids  in  the  coarse  sand  with  which  these  channels  are  filled  could 
be  assumed  to  be  28^  of  the  entire  area,  which  they  are  approximately,  the 


MASONRY  DAMS. 


213 


rate  of  flow  established  by  the  discharge  of  15  inches  (0.3  second-foot) 
would  be  precisely  one  mile  per  annum,  a  velocity  which  coincides  with  the 
observations  of  several  authorities  on  the  rate  of  flow  through  sand  of  that 
character.  It  may  be  noted  in  this  connection  that  the  volume  of  under- 
flow in  sandy  rivers  is  generally  vastly  smaller  than  the  popular  conception 
of  it,  and  for  this  reason  submerged  dams  for  raising  this  underflow  are 
usually  commercial  failures,  except  where  the  material  of  the  stream-bed  is 
a  coarse  gravel,  with  little  or  no  fine  sand  intermingled. 


Quarry 


'ffubbte  Masonry 
3/  92' 
'96' 


Fig.  105.— ORoss-SECTioNe  of  Agua  Fria  Diverting-dam  and  Storage-reservoir 

Dam,  Arizona. 

The  masonry  used  in  the  diverting-dam  is  a  rough  rubble,  faced  with 
coursed  ashlar,  mostly  laid  in  a  mortar  of  hydraulic  lime  of  good  quality, 
burned  about  20  miles  from  the  dam.  (See  Figs.  106  and  107.)  For  a 
portion  of  the  work  a  small  amount  of  Portland  cement,  made  in  Colton, 
California,  was  used.  The  rock  was  handled  by  a  Lidgerwood  cableway, 
with  a  span  of  700  feet.  The  excavation  of  foundations,  amounting  to 
about  12,000  cubic  yards,  was  accomplished  by  teams  and  scrapers,  the 
water  being  handled  by  centrifugal  pumps. 

In  October,  1895,  a  flood  came  which  poured  over  the  fresh  masonry 
for  several  hours  to  the  depth  of  8  feet,  and  finally  carried  away  a  section 
100  feet  long,  12  feet  deep,  near  the  west  end.  The  partial  failure  of  the 
wall  is  accounted  for  by  the  fact  that  in  laying  the  masonry  each  course  was 
leveled  off  smoothly  with  mortar,  in  the  fashion  to  which  brick-masons  are 
addicted  in  laying  up  house-walls.  There  was  thus  little  bond  between  the 
courses,  which  is  so  essential  in  dam-work.    A  view  of  the  dam,  taken  from 


2U        BESEBVOIRS  FOR  IRRIGAIION.  WAmit-POWER.  ETC. 

the  oiuml  bank,  is  shown  in  Fig.  107,  repro.duccd  by  permission  from  a 
paper  entitled  "Irrigation  near  l'li(Bnix,  Arizona,"  by  Arthur  1.  Uavis 
C  E    Ilydrographer,  U.  S.  Geological  Survey,  being  No.  2  ot  the  series  of 
"Water-supply  and  Irrigation  Papers,"  from  which  some  of  the  data  for 
the  foregoing  description  are  derived. 

In  addition  to  the  Frog  Tanks  reservoir-site  the  company  have  a  second 
location,  8  miles  higher  up  tlie  river,  where  the  gorge  is  but  362  feet  wide 
at  tlie  river-bed,  in  solid  rock,  and  but  500  feet  wide  at  a  height  of  m 
feet  This  basin  is  said  to  have  a  capacity  of  150,000  acre-feet,  with  a  dam 
150  feet  high  The  watershed,  whicli  drains  the  east  slopes  of  the  Brad- 
shaw  Mountains,  reaches  summit  elevations  of  6000  to  8000  feet.  A 
reasonable  estimate  of  rainfall  and  run-off  from  this  shed  is  a  P;;eciFt-tion 
of  16  inches  and  an  annual  run-off  of  15^,  which  would  yield  142,300  acre- 

Storage-reservoirs  for  Water-Supply  Along  the  Line  of  the  Santa  F6 
Pacific  Railway  in  Arizona.-The  northern  portion  of  Arizona,  traversed 
by  the  Santa  Fe  Pacific  Railway,  is  an  elevated  plateau  draining  into  the 
Colorado  Canyon  on  the  north,  the  Colorado  River  on  the  west,  and  the 
Verde  Salt,  and  Gila  rivers  on  the  south.    This  region  has  a  maximum 
elevation  of  over  7000  feet  along  the  railway  and  receives  a  greater  precip- 
itation than  the  lower  altitudes  in  the  southern  part  of  the  territory,  bu  it 
is  largelv  capped  with  volcanic  lava  and  indurated  ash,  through  which  the 
water  from  rain  and  melted  snow  rapidly  sinks  and  disappears.  Living 
springs  and  streams  are  therefore  infrequent,  and  the  water-supply  for  rail- 
way purposes  is  so  unevenly  distributed  as  to  necessitate  the  impounding  of 
flood-waters  in  artificial  reservoirs.     This  necessity  is  chiefly  due  to  the 
general  absence,  in  the  valleys  of  that  region,  of  beds  of  coarse  sand  and 
travel,  which  constitute  nature's  storage-basins.    The  railway  company  to 
avoid  hauling  water  from  point  to  point  over  this  section  of  the  road,  has 
constructed  several  substantial  dams  for  storage  purposes  at  convenient 
points  near  the  line  of  the  railway,  all  of  an  interesting  character  m  then- 
construction  from  an  engineering  standpoint,  although  unimportant  m  the 
volume  of  water  stored  compared  with  works  located  in  more  favorable 
localities.    These  reservoirs  are  the  following :  ■  


Locality. 

Volume  Stored. 

Cubic  Feet. 

Acre-ft. 

30,651,000 
4,950,000 
14.700,000 
20,798,000 

703 
113.6 

838 
488 

Height 

of 

r»am. 
Feet. 

Character  of  Dam. 

16 

Masonry,  submerged 

68 

Masonry 

4(5 

Steel 

46 

Masonry 

70.4 

Masonry 

Elevation 

above 
Sea-level. 


5884 
5445 
7000 
6282 


LIBKAWY 

;  »  THE 
^:UN^y£RSiTy  of  lLUNOl 


0^  THE 
♦*NlV£RSITVoflLLINOIi^ 


MASONBT  DAMS. 


219 


The  Kingman  Submerged  Dam. — About  one  mile  west  of  Kingman  the 
railway  company  have  a  well  sunk  in  the  gravelly  bed  of  Eailroad  Canyon, 
from  which  they  pump  water  for  filling  their  tank  at  Kingman  to 
supply  the  town,  as  well  as  the  locomotives  of  the  railway.  To  increase 
this  supply  and  to  furnish  water  by  gravity  to  another  tank  4  miles 
below.,  a  masonry  dam  was  built  on  bed-rock  to  intercept  the  underflow  of 
the  stream  and  store  water  in  the  gravel  bed  above  the  dam.  The  dam 
consisted  of  a  slender  masonry  wall,  2  feet  thick  at  top,  6  feet  thick  at  base, 
and  16  feet  high,  crossing  the  canyon  from  side  to  side  and  reaching  up 
nearly  to  the  surface  of  the  stream-bed.  A  trench  was  excavated  in  a 
straight  line,  the  dam  was  built,  and  the  gravel  restored  to  its  natural 
position,  so  that  floods  pass  over  its  top  unobstructed.  The  dam  is  thus 
entirely  concealed  from  view.    At  the  northerly  end  of  the  dam  it  was 


Fig.  108. — Submerged  Storage-  and  Diverting-dam,  near  Kingman,  Arizona. 


necessary  to  tunnel  some  distance  under  the  railway  in  gravelly  formation 
in  order  to  carry  the  masonry  to  the  bed-i'ock  wall  of  the  canyon  on  that 
side.  This  tunnel  was  made  12  feet  wide,  20  feet  high,  and  about  30  feet 
long,  the  top  of  the  tunnel  being  16  feet  below  the  rails.  A  6-inch  cast- 
iron  outlet-pipe  is  built  through  the  dam  12  feet  below  the  top,  at  one  side. 
Four  feet  above  the  dam  an  elbow  is  placed,  upturned  vertically,  and  an  8- 
inch  wrought-iron  stand-pipe  10  feet  long  is  inserted  in  the  elbow.  This 
stand-pipe  is  perforated  with  |-inch  holes,  placed  ^  inch  apart,  for  straining 
the  water,  the  top  being  capped.  The  gravel  reservoir  is  kept  filled  to  the 
top  of  the  dam  by  the  natural  underflow,  and  thus  the  town  well  is  sup- 
plied and  the  lower  tank  automatically  fllled  by  gravity,  the  discharge 
being  controlled  by  a  float.  No  shortage  of  water  has  been  experienced 
since  the  dam  was  built  in  1897.  The  dam  is  173  feet  long  on  top,  and 
contains  320  cubic  yards  of  masonry.    (See  Fig.  108.) 

The  Seligman  Dam.— This  structure  was  begun  June  25,  1897,  and 
completed  Feb.  28,  1898.  It  is  the  largest  and  most  expensive  of  all  the 
structures  of  its  class  built  by  the  railroad  company.  It  is  located  three 
miles  southeast  of  the  town  of  Seligman,  an  important  division  terminal 


220 


liESEliVOlUS  FOR  IRllIGATIOJY,   WATEU  POWEli,  ETC. 


5104  feet  above  sen-level.  The  dimensions  of  the  dam  are  as  follows: 
Length  at  base,  145  feet;  length  on  crest,  643  feet;  height,  08  feet;  thick- 
ness at  base,  47.77  feet;  thickness  3.1  ft.  below  the  over  flow  or  5.1  ft.  below 
the  crest,  5.14  feet;  thickness  at  top,  1.75  feet.  It  is  arched  up-stream 
with  a  radius  of  800  feet  from  the  line  of  the  water-face.  The  cubica 
contents  are  18,161.4  cubic  yards,  divided  as  follows: 

Concrete  in  foundation   300     cubic  yards. 

Rough  rubble  in  core   13,843.4     "  " 

Dressed  ashk:-   3,817.7  " 

Coping   20Ue3 

The  work  was  done  by  contract,  the  I'ailway  company  furnishing  the 
cement  and  delivering  the  stone,  sand,  and  cement  on  cars  to  the  dam-site, 
the  contractor  quarrying  and  loading  the  stone.    The  rubble  sandstone  was 


Fig.  109  — Seligman  Dam,  Arizona. 


hauled  43  miles  from  Eock  Butte,  on  the  S.  F.,  P.  &  P.  R.R.,  the  facing- 
stone  was  hauled  175  miles  from  Holbrook,  and  the  sand  150  miles  from 
the  Sacramento  Wash.  The  contract  prices  were:  $9  per  yard  for  coping, 
$6.50  per  yard  for  facings,  14.62  for  rubble,  and  $2.81  for  concrete.  The 
total  cost  of  the  dam  was  in  excess  of  $150,000. 

The  character  of  the  masonry  is  well  shown  by  the  photograph  (Fig 
109)  of  the  lower  face  during  erection.    Fig.  110  shows  the  water-face  and 
end  buttresses.    The  water  appearing  in  the  foreground  is  retained  by  a 
low  earth  dam  that  had  been  in  use  for  some  time  prior  to  the  construction 
of  the  masonry  dam.    The  center  of  the  dam  is  depressed  two  feet  beloT\^ 


MASONRY  BAMS. 


221 


the  crest  for  a  distance  of  340  feet,  and  curved  in  the  form  of  the  segment 
of  a  vertical  parabola  for  the  overflow,  which  is  the  true  form  taken  by 
falling  water  pouring  over  a  weir.  The  maximum  capacity  of  this  spillway 
is  3400  second-feet,  and  as  the  watershed  tributary  to  the  dam  is  but  18 
square  miles,  the  capacity  provided  is  doubtless  greatly  in  excess  of  what 
will  ever  be  required. 

The  outlets  to  the  reservoir  consist  of  two  8 -inch  cast-iron  pipes,  placed 
6  feet  apart  between  centers,  54  feet  below  the  crest  of  dam,  on  the  north 
side  of  the  ravine,  and  one  of  similar  size  on  the  south  side,  used  as  a 
waste.  These  pipes  are  connected  with  vertical  stand-pipes,  inside  the 
reservoir,  standing  10  feet  high  and  6  feet  from  the  face  of  the  dam. 
They  are  of  wrought  iron,  capped  at  top  and  perforated  with  f-inch  holes, 
bored  |-  inch  from  center  to  center.  They  form  the  intake  and  serve  to 
strain  the  water,  and  keep  out  trash  fiom  the  pipes.     Gate-valves  are 


Fig.  110  — Seligman  Dam,  Arizona.  View  of  Uppek  Face  duping  Constetjction. 
placed  in  each  pipe  at  the  outside  toe  of  the  dam,  and  the  pipes  are  reduced 
below  the  valves  to  6  inches  in  diameter,  where  one  of  them  is  connected 
with  the  main  pipe  line  leading  to  Seligman.  The  reservoir  is  3000  feet 
long,  and  covers  an  area  of  25^^  acres.  Its  maximum  capacity  is  30,651,000 
cubic  feet,  or  703  acre-feet,  of  which  one-third  is  in  the  upper  ten  feet. 
The  average  loss  by  evaporation  from  January  to  June  inclusive  was  found 
to  be  0.03  foot  per  day,  or  an  annual  rate  of  10.95  feet.  This  loss,  applied 
to  the  mean  surface  exposed,  would  amount  to  15^  per  cent  of  the  entire 
volume  in  809  days,  assuming  an  average  daily  consumption  of  16,000 
cubic  feet  during  that  time.  A  full  reservoir  is  therefore  expected  to 
supply  120,000  gallons  daily  for  2^  years,  after  deducting  evaporation. 
The  catchment  is  somewhat  unreliable,  and  the  reservoir  did  not  receive  any 
water  for  the  first  two  years  after  it  was  built.  Fig.  Ill  illustrates  the  section 
of  the  canyon  and  the  profile  of  the  dam.  The  fine  appearance  which  the 
immense  mass  of  masonry  presents  inspires  regret  that  it  should  be  hidden 
from  public  view  from  passing  trains,  although  it  is  easily  accessible  to 
those  who  care  to  step  off  at  Seligman  and  inspect  it. 


222         RESERVOmS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


The  Ash  Fork  Steel  Dam. — This  structure  is  tho  first  oue  of  its  class  that 
has  ever  been  erected,  and  lias  so  many  novel  features  of  an  experimental 
character  that  it  is  si)ccially  interesting-  and  instructive  to  the  engineei'ing 
profession.  It  was  designed  by  F.  11.  Bainbridge,  C.E.,  of  Chicago,  and 
was  erected  in  1897  on  Johnson  Canyon,  at  a  point  4.3  miles  east  of  Ash 
Fork,  the  junction  of  the  Santa  Fe  Pacific  with  the  Santa  Fe,  Prescott  and 
I'hoenix  Kailroad,  The  dam  is  one  mile  south  of  the  track  of  the  former 
road.  The  steel  portion  of  the  dam  is  184  feet  long,  4G  feet  maximum 
height  for  GO  feet  in  center.  This  steel  structure  connects  with  masonry 
walls  at  each  end,  which  complete  the  dam  across  the  gorge  to  a  total  length 
of  300  feet  on  top.  The  steel  structure  consists  of  a  series  of  twenty-four 
triangular  bents  or  frames,  standing  vertically  on  the  lower  side,  with  a 
batter  of  1  to  1  on  the  upper.    These  frames  are  composed  of  heavy  I  beams, 


FiGo  111. — Section  and  Phofilb  of  Seligman  Dam,  Aiuzona. 


with  diagonal  struts  and  braces,  resting  on  concrete  foundations,  and  placed 
8  feet  apart,  center  to  center,  all  well  anchored  into  the  bed-rock  on  the 
concrete  base,  and  braced  laterally  in  pairs.  The  dimensions  of  the  bents 
vary  with  their  height.  The  end  bents  are  12  to  21  feet  in  height,  nine  in 
number;  four  of  the  bents  are  33  feet  high,  and  the  remainder  from  33  feet 
to  41  feet  10  inches  high.  The  batter-posts,  to  which  the  face-plates  are 
riveted,  are  of  20-inch  I  beams,  the  longest  being  66.5  feet.  The  face  of 
the  dam  is  composed  of  curved  plates  of  steel,  f  inch  thick,  8'  lOf"  wide, 
and  8  feet  long,  the  concave  side  being  placed  towards  the  water.  They 
thus  present  the  a])pearance  of  a  series  of  troughs  or  channels  between  the 
supports.  The  bent  phites  do' not  extend  into  the  concrete  at  the  base,  but 
the  bottom  course  consists  of  flat  plates,  and  the  course  next  to  the  bottom 
is  dished  in  the  form  of  a  segment  of  a  sphere,  making  the  transition 
between  the  curved  and  straight  form.  The  edges  of  the  plates  are  beveled 
for  calking,  and  riveted  together  with  soft  iron  rivets.  The  joint  between 
the  steel  and  masonry  structures  at  the  ends  is  formed  by  embedding  flat 
plates  into  the  concrete,  the  face  of  which  has  the  same  slope  as  the  face  of 


MASONRY  DAMS. 


223 


the  steelwork.  The  abutments  project  8  inches  beyond  the  line  of  the  face- 
plates. The  masonry- work  consists  of  342.6  cubic  yards  of  rubble  and 
1087  cubic  yards  of  concrete,  and  there  was  used  in  the  work  a  total  of 
1751  barrels  of  Portland  cement.  The  work  was  begun  October  7,  1897, 
and  completed  March  5,  1898,  under  the  supervision  of  E.  B.  Burn?, 
Chief  Engineer,  Santa  Fe  Pacific  Railway,  Mr.  W.  D.  Nicholson,  Assistant 
Engineer,  being  directly  in  charge. 

The  dam  is  designed  to  carry  flood-water  over  the  top  of  the  steel 
structure.  The  steel  plates  are  carried  over  the  top  of  the  frame,  forming  a 
rounded  apron  to  carry  the  overfall  beyond  the  line  of  posts.  This  apron, 
connecting  with  the  curved  inner  plates,  forms  a  series  of  trough-like 
channels  between  posts,  1.3  feet  deep  at  center.  The  abutment  wall  at  the 
east  end  of  the  dam  is  2  feet  higher  than  the  bottom  of  the  spillway  chan- 
nels, and  that  at  the  west  end  is  nearly  8  feet  higher.  The  rock  at  the 
dam-site  is  volcanic  in  origin,  very  hard  on  the  surface  where  exposed,  but 
containing  occasional  pockets  of  ashes  or  cinders,  and  badly  broken  by  seams. 
The  rock  excavated  for  foundations  was  used  for  concrete  and  rubble 
masonry.  The  concrete  was  mixed  in  the  proportion  of  1  of  Portland 
cement  to  3  of  sand  and  5  of  broken  stone.  The  outlets  consist  of  two 
6-inch  cast-iron  pipes  placed  6  feet  apart,  with  perforated  stand-pipes,  10 
feet  high,  inside  the  reservoir,  similar  to  those  at  the  Seligman  dam.  The 
pipes  are  embedded  in  the  concrete  28  feet  below  the  top  of  the  dam,  and 
reduced  to  4"  diameter  at  a  point  16  feet  below  the  gates  that  are  nlaced  at 
the  toe  of  the  masonry.  The  fall  in  the  pipe-line,  4.3  miles  long,  is  200 
feet  from  base  of  dam  to  the  top  of  the  water-tank  at  Ash  Fork. 

The  reservoir  has  a  capacity  of  37,023,000  gallons,  or  4,950,000  cubic 
feet,  and  receives  the  drainage  from  26  square  miles  of  watershed.  The 
average  consumption  is  estimated  at  90,000  gallons  per  day,  or  three-fourths 
that  of  Seligman.  The  loss  by  evaporation  is  expected  to  be  40^  to  50^  of 
the  total  supply,  but,  inasmuch  as  it  will  receive  water  from  summer  rains 
as  well  as  from  melting  snows,  it  is  anticipated  that  the  supply  will  be  main- 
tained equal  to  tlie  ordinary  demand. 

It  cannot  be  said  that  this  experimental  steel  dam,  the  first  of  its  class 
that  has  been  erected,  is  entirely  successful,  and  it  is  doubtful  if  the  com- 
pany, with  the  experience  already  had  in  two  years  of  service,  would  care 
to  repeat  it  or  recommend  that  class  of  construction  in  lieu  of  something 
more  substantial  and  permanent.  It  has  been  found  difficult,  and  in  fact 
impossible,  to  make  a  tight  joint  between  the  steel  and  masonry  work.  The 
structure  leaks  quite  badly  at  both  ends.  The  water  also  follows  down  the 
face-plates  on  the  up-stream  side  and  comes  out  on  the  down-stream  side, 
notwithstanding  that  concrete  has  been  rammed  in  on  both  sides  of  the 
plates  for  a  distance  of  5  feet. 

The  total  weight  of  steel  in  the  structure  is  478,704  lbs.,  which  was 


224         EESEllVOIliS  FOR  IIUIIOATION,  WATER-POWER,  ETC. 


fnimcd  and  erected  by  the  Wisconsin  Bridge  and  Iron  Company  at  a  cost  of 
$55.78  per  ton  of  2000  lbs.    The  detailed  cost  of  the  entire  darn  is  given 


as  follows: 

MATERIAL. 

Lumber,  etc.,  in  buildings   1659.94 

Explosives  and  tools  used  in  excavating   937.20 

Corrugated  iron  and  nails  in  facing.   181.02 

Eubble  stone   155.25 

Paint  and  oil  for  painting  dam   213.49 

Cement,  1926  barrels   5,774.92 

Steel  in  dam,  erected   13,351.05 

Fencing  for  reservoir   409.26 


Total  material..'  121,682.13 

LABOR. 

Spur-track  •  •  ■  •  ^l^.OO 

Building  camp   272.75 

Hauling  material     3,378.10 

Excavating  and  laying  masonry   15,440.36 

Engineering  and  superintendence   3,102.83 

Plans  and  tests  of  metal   233.63 

i^'reiffht  on  metal   1,651.30 


Total  labor  24,093.97 


Total  cost  of  dam  complete   145,776.10 

The  pipe-line  to  Ash  Fork  cost   15,978.70 

Figs.  112  and  113  give  an  excellent  general  idea  of  the  construction. 
Fig.  114  shows  a  portion  of  the  reservoir,  and  represents  clearly  the  igneous 
rock  formation  of  the  canyon  in  which  it  is  located. 

The  Williams  Dam.— The  first  of  the  series  of  dams  for  storage  erected 
•by  the  railway  company  was  constructed  near  the  town  of  Williams  in  1894. 
It  has  an  extreme  height  of  46  feet,  is  385  feet  long  on  the  crest,  50  feet 
long  at  the  base,  where  its  thickness  is  32  feet.  The  thickness  at  top  is 
4  feet.  It  is  arched  up-stream  with  a  radius  of  573  feet  from  the  line  of 
the  vertical  water-face.  The  dam  contains  5226  yards  of  masonry,  and 
consumed  3640  barrels  of  cement  in  construction.  Its  cost  was  $52,838. 
The  dam  has  been  a  serviceable  structure.  The  capacity  of  the  reservoir  is 
110,000,000  gallons.  The  watershed  area  is  not  definitely  known,  but  is 
small. 


MASONRY  DAMS. 


225 


The  Walnut  Canyon  Dam. — Walnut  Canyon  is  a  tributary  of  the  Little 
Colorado  River,  which  heads  in  Mormon  Mt.  a  little  south  and  east  of 
Flagstaff.    Tlie  watershed  area  above  the  dam  is  126  square  miles,  which 


Fm.   112. — Ash  Fork,   Arizona,   Steel  Dam,  View  of  Steel  Construction 

PROM  Lower  Side. 


ordinarily  affords  a  much  greater  run-off  than  the  storage  capacity  of  tho 
reservoir.  The  geological  formation  of  the  canyon  walls  at  the  dam-site  is 
sandstone  in  heavy  layers  or  strata  in  nearly  level  beds.    The  bottom  of  the 


Fig.  113.— Ash  Fork,  Steel  Dam,  Showing  Frame  ready  to  receive  Plates- 


canyon  was  so  filled  with  debris  of  earth  and  stone  that  it  was  necessary  to 
excavate  28  feet  below  the  surface  to  reach  bed-rock,  on  which  the  dam  was 
erected.  The  width  at  this  point  was  but  30  feet,  at  the  surface  of  stream- 
bed  120  feet,  and  at  the  top  of  the  dam  268  feet.    The  extreme  height  of 


226         liESEliVOlRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 

the  diim  is  77.(5  feet.  Its  thickness  at  base  is  G1.5  feet.  The  water-face  is 
vertical,  while  the  upper  face  lias  a  batter  of  7.}  inches  to  the  foot  between 
the  vertical  curves  at  top  and  toe.  The  top  is  rounded  in  parabolic  form 
to  a  tliickness  of  13  feet  at  a  point  10.4  feet  below  the  crest,  to  form  an 
easy  overflow  for  surplus  waste  water,  while  at  the  base  the  wall  is  vertical 
for  10  feet,  above  which  is  a  vertical  curve,  tangential  to  the  horizon,  pass- 
ing through  58°  of  arc,  to  a  point  4(3.4  feet  below  the  top,  where  the  thick- 
ness is  o5^5  feet.  This  design  forms  an  exceedingly  massive  structure  with 
unusually  large  factor  of  safety.    The  dam  is  arched  up-stream  with  a  radius 


Fig.  114.— Ash  Fork  Eeservoik. 

of  400  feet  to  the  line  of  the  water-face.  The  masonry  consists  of  5244 
cubic  yards  of  heart  rubble,  1572  cubic  yards  of  facing  ashlar  masonry  m 
irregular  courses,  with  dressed  beds,  and  80  cubic  yards  of  cut  copmg-stone- 
a  total  of  (3986  cubic  vards.  There  were  6070  barrels  of  Portland  cement 
used  in  construction.  The  total  cost,  exclusive  of  excavation,  was  about 
$55,000.    The  stone  used  was  quarried  at  the  dam-site  and  was  of  good 

quality.  ,   .  <?  •  f 

The  outlets  consist  of  two  10-inch  cast-iron  pipes,  placed  6  feet  apart,  at 
an  elevation  of  30.4  feet  below  the  top  of  the  dam,  10  feet  above  the  stream- 
bed  Vertical  strainer-pipes,  10  feet  high,  are  placed  over  the  upper  ends 
of  the  outlets  in  the  reservoir,  6  feet  from  the  face  of  the  dam.  Outside 
the  pipes  are  controlled  by  10-inch  Ludlow  gates,  and  are  reduced  to  8 
inches  iiameter  below  the  gates.  The  main  pipe-line  from  the  dam  follows 
the  canyon  for  ^  miles  to  the  railroad  crossing,  and  thence  follows  the  track 
easterly  12  miles  further  to  a  tank. 

Fig.  115  is  a  view  of  the  dam  from  below  when  nearly  completed,  -b  ig. 
116  shows  the  profile  of  the  dam  as  constructed,  and  a  section  of  the  canyon 
at  the  dam-site. 


MASONRY  DAMS. 


227 


The  reservoir  was  filled  for  the  first  time  on  the  8th  of  March,  1898,  and 
if  it  had  been  water-tight  should  have  supplied  an  estimated  consumption  of 
60,000  gallons  daily  for  more  than  two  years,  allowing  for  a  daily  evapora- 


Fig.  115.  — Walnut  Canyon  Dam,  Akizona. 


t.on  loss  of  0.03  foot.  The  water,  however,  disappeared  very  rapidly,  and 
by  September  20th  was  all  gone,  having  lasted  but  196  days  instead  of  the 
estimated  356  days.    The  draft  for  consumption  on  the  road  was  not  greater 


Fig.  116  —Section  and  Pkopile  of  Walnut  Canyon  Dam,  Arizona. 


than  had  been  assumed  in  the  original  calculation,  and  the  excessive  loss 
could  only  be  accounted  for  by  percolation  through  the  sandstone  or  through 
the  seams  separating  the  underlying  limestone  from  the  sandstone.  It  is 
hoped  that  the  reservoir  will  ultimately  puddle  itself  and  become  tight,  and 


2'28 


UKSKRVOIRS  FOR  IRRIQATION,  WATER-POWER,  ETC. 


efforts  uvc  being  made  to  assist  the  process  by  plowing  and  loosening  clay 
soil  at  points  above.  It  is  nnfortunate  that  the  usefulness  of  such  a  line 
structure  should  be  curtailed  by  this  unexpected  leakage  in  the  walls  of  the 
reservoir,  but  it  is  possible  that  the  loss  of  water  may  gradually  lessen  and 
finally  cease.  This  experience  illustrates,  however,  one  of  the  vicissitudes 
attending  the  impounding  of  water.  Under  the  most  favorable  conditions 
the  annual  loss  by  evaporation  on  this  reservoir  would  be  nearly  35^  of  the 
volume  of  storage  capacity.  No  run-off  was  caught  during  the  summer  of 
1899,  and  in  the  latter  part  of  August  it  was  still  dry.  The  entire  series  of 
reservoir  dams  have  been  constructed  under  the  supervision  of  Mr.  R.  B. 


Fig.  117.— Lynx  Cheek  Dam,  Arizona,  aftek  Rupture  by  Flood.  View 

from  below. 

Burns,  Chief  Engineer,  Santa  Fe  Pacific  Railway,  to  whom  the  writer  is 
indebted  for  the  data  concerning  the  works  and  the  views  which  illustrate 
them. 

Lynx  Creek  Dam,  Arizona.— This  structure  was  located  12  miles  east  ot 
Prescott,  Arizona,  and  was  designed  to  impound  water  for  hydraulic  mining 
on  Lynx  Creek,  some  4  miles  below.  It  was  intended  for  an  ultimate  height 
of  50  feet,  and  was  started  with  a  base  of  28  feet.  When  it  had  reached 
a  height  of  28  feet  on  the  up-stream  side,  the  lower  edge  of  the  crest  being 
2  feet  higher,  it  was  roughly  squared  off  with  the  intention  of  addmg  the 
remaining  portion  at  a  later  date,  when  a  sudden  flood  overtopped  the  dam 
and  ruptured  it,  taking  out  about  35  feet  of  the  masonry  down  to  the  bed- 
rock. The  break  is  shown  by  the  view,  Fig.  117,  looking  up-stream.  It 
occurred  in  1891,  and  the  dam  has  never  been  rebuilt.  The  dimensions  of 
the  dam  were  ample  to  withstand  any  overflow  to  be  expected  from  the 


MASONRY  DAMS. 


229 


floods  draining  the  tributary  watershed  of  30  square  miles  of  territory,  from 
5500  to  7500  feet  in  elevation,  had  the  masonry  been  of  reasonably  good 
quality.  The  failure,  therefore,  was  clearly  due  to  poor  workmanship  and 
unsuitable  materials.  The  dam  was  150  feet  long  on  crest,  and  was  built 
with  a  central  angle  of  about  165°  opposed  to  the  direction  of  the  current, 
the  up-stream  face  being  vertical.  The  wall  consisted  of  a  thin  facing  of 
hand-laid  masonry,  not  over  one  foot  thick,  the  core  being  filled  with  a  weak 
concrete  of  fine  gravel,  stone,  spawls,  and  sand.  The  section  of  the  dam  as 
constructed  is  clearly  seen  from  the  photograph  (Fig.  118).  Considerable 


Fig.  118. — Lynx  Ckeek  Dam,  Arizona.    Section  SHowiNa  Facing  Walls  and 

Concrete  Hearting. 


lime  was  used  with  the  cement,  which  was  of  poor  quality,  and  the  concrete, 
though  ten  years  old,  possesses  so  little  cohesion  that  it  may  be  crumbled 
with  a  light  touch.  The  cement  used  averaged  but  1  barrel  to  6  cubic 
yards  of  masonry.  The  failure  of  the  dam,  under  all  the  circumstances, 
might  have  been  anticipated.  It  is  referred  to  here  merely  as  an  example 
to  illustrate  the  natural  consequences  that  must  follow  any  carelessness  or 
lack  of  attention  to  proper  selection  of  materials  and  skill  of  construction 
in  masonry  or  concrete  dams  that  must  withstand  the  erosive  action  of 
floods  as  well  as  normal  water-pressure. 

Concrete  Dams  of  Portland,  Oregon. — Among  recent  constructions  of 
concrete  masonry  three  dams  designed  and  erected  by  the  writer  for  the 
water-works  of  Portland,  Oregon,  in  1894,  maybe  classed  as  worthy  of  note. 
They  were  built  for  the  purpose  of  forming  distributing  reservoirs,  and  were 
located  across  natural  ravines,  or  embayments  in  the  hills,  the  reservoir  space 
being  largely  augmented  by  excavation,  and  the  slopes  covered  with  a  lining 


230 


llESERVOIRS  FOR  IRRIOATWN,  WATER  POWER,  EFG. 


of  concrete.    One  of  these  diims,  showu  in         119,  closes  reservoir  No.  1 
ou  the  side  of  Mount  Tabor,  and  is  35  feet  liigh,  300  feet  long,  with  a  base 
of  18  feet  and  top  width  of  6  feet.     The  reservoir  capacity  is  12,000,000 
gallons.     Beliind  the  dam  the  material  excavated  from  the  reservoir  was 
placed,  forming  a  heavy  embankment  whose  top  width  is  100  feet.    This  is 
such  an  immovable  barrier  that  the  chief  function  of  the  concrete  wall  is  to 
act  as  a  retaining-wall  for  the  inner  slope  of  the  earth-fill,  and  to  form  a 
part  of  the  reservoir  lining.    The  reservoir  receives  the  water  delivered  by  a 
steel-pipe  line  24  miles  long,  amounting  at  maximum  capacity  to  22,400,000 
gallons  daily,  and  distributes  it  to  three  other  reservoirs,  one  of  which  is  but 
2000  feet  distant,  shown  in  the  photograph  Fig.  121,  and  the  other  two  are 
five  miles  away,  across  the  Willamette  River,  and  designated  as  reservoirs  3 
and  4  (Fig.  120).  Reservoir  No.  3,  high  service,  has  a  dam  200  feet  long  which 
is  arched'^up-stream  with  a  radiu^  of  300  feet.    Its  height  is  60  feet,  base  40 
feet,  top  width  15.5  feet,  carrying  on  its  crest  a  driveway  of  the  City  Park,  in 
which  it  is  located.    This  is  the  only  dam  of  the  three  which  is  curved,  and 
the  only  one  which  does  not  exhibit  some  slight  expansion-cracks.    The  dam 
forming  reservoir  No.  4,  low  service,  is  50  feet  high,  350  feet  long,  and  40 
ieet  wide  at  base.     The  faces  of  these  two  dams,  both  of  which  are  in  the 
City  Park,  are  moulded  and  chiseled  to  resemble  stone,  and  considerable 
ornamentation  has  been  done  on  the  parapets  and  about  the  gate-houses,  as 
shown  in  Fig.  120,  to  which  the  concrete  aud  iron  construction  lends  itself 
to  good  advantage.     It  is  needless  to  add  that  the  dams  of  the  dimensions 
given  are  of  safe  gravity  profile,  with  ample  factors  of  safety. 

Basin  Creek  Dam,  Montana.— This  dam  was  built  in  1893-95  to  impound 
water  for  a  portion  of  the  domestic  supply  of  the  city  of  Butte,  Montana, 
and  is  located  13  miles  south  of  the  city,  on  Basin  Creek.  It  was  designed 
by  Chester  B.  Davis,  M.  Am.  Soc.  C.  E.,  and  constructed  under  direction 
of  Eugene  Carroll,  C.B.,  Chief  Engineer.  The  construction  was  described 
in  Engineering  December  17,  1892,  Aug.  7,  1893,  and  Sept.  5,  1895, 

in  communications  prepared  by  these  engineers,  from  which  the  following 
data  have  been  taken.  The  dam  is  constructed  of  large  stone,  with  spaces 
thoroughly  tilled  with  concrete,  made  of  crushed  granite  3  parts,  sand  3 
parts,  and  Yankton  Portland  cement  1  part.  It  was  designed  for  an 
ultimate  height  of  120  feet  above  the  lowest  foundation,  assumed  to  be  at 
elevation  5780  feet  above  sea-level,  or  30  feet  below  stream-bed,  and  was 
curved  up-stream  with  a  radius  of  350  feet  from  its  water-face.  The  thick- 
ness at  base  was  to  be  83  feet,  and  at  top  10  feet  ;  up-stream  face  vertical. 
At  full  height  it  would  impound  about  1,000,000,000  gallons  (3069  acre- 
feet),  covering  an  area  of  130  acres  to  a  mean  depth  of  23.6  feet.  The  dam 
was  not  completed  higher  than  to  the  5860-foot  contour,  or  40  feet  below 
the  projected  crest,  although  its  actual  maximum  height  is  88  feet,  of 
which  28  feet  is  below  the  stream-bed  level,  and  it  now  can  impound 


MASONRY  DAMS. 


235 


200,000,000  gallons.  The  contents  of  the  dam  are  11,500  cubic  yards  of 
masonry.  Its  top  length  is  259  feet.  Three  20-inch  pipes  are  laid  through 
the  dam  at  its  center,  at  the  creek-bed  level,  two  of  which  are  used  for  blow- 
off.  These  pipes  are  controlled  by  plain  cover- valves,  resting  on  upturned 
elbows  inside  the  dam,  and  raised  by  a  windlass  from  the  top.  Gate-valves 
on  the  pipes  below  the  dam  give  secondary  control. 

The  materials  of  construction  were  hauled  by  a  Lidgerwood  cableway, 
witli  a  clear  span  of  892  feet,  the  main  cable  being  2^  inches  diameter,  sus- 


FiG.  121.— RESERvom  No.  2,  Portland,  Oregon,  showing  Aerating  Fountain 

125  FEET  HIGH. 


pended  GO  feet  higher  than  the  120-foot  crest-line.  This  cableway  crossed 
over  the  quarry,  and  was  stretched  on  the  chord  of  the  inner  face  of  the 
dam.  The  loads  were  swung  either  side  of  this  line  by  using  a  single  horse 
pulling  from  a  rope  attached  to  the  load  and  leading  back  over  a  sheave  to 
a  snubbing-post.  The  limited  space  made  the  use  of  derricks  for  this 
purpose  inconvenient.  For  a  distance  of  9  miles  from  the  dam  the  main 
conduit  to  the  city  consists  of  a  wooden-stave  pipe,  24  inches  in  diameter, 
built  by  the  Excelsior  Wood-stave  Pipe  Co.  of  San  Francisco,  of  which 
Mr.  D.  C.  Henny  is  manager  and  engineer. 

A  Dam  uKder  640-foot  Head. — A  curiosity  in  the  line  of  masonry  dams 
is  the  one  built  in  the  Curry  mine,  at  Norway,  Michigan,  to  close  a  drift 
6  feet  wide,  7|  feet  high,  and  thereby  cut  off  a  troublesome  stream  of  water. 
It  was  built  of  sandstone,  arched  against  the  direction  of  the  pressure,  with 
a,  thickness  of  10  feet,  and  laid  in  Hilton-cement  mortar,  in  the  proportion 


236         RESERV01118  FOR  IRRIOATION,  WATER-POWER,  ETC. 


of  1  to  2  of  sand.  The  dum  (Fig.  122)  is  nearly  800  feet  below  the  surface, 
and  when  the  water  tills  behind  it  is  subjected  to  a  pressure  of  277  lbs.  to 
the  square  inch,  equal  to  a  static  head  of  640  feet,  or  a  total  pressure 
against  the  dam  of  over  800  tons.  The  dam  was  designed  and  built  by 
Wm.  Kelly,  M.  Am.  Inst.  M.  E.,  and  doubtless  affords  the  most  extraordi- 


Longitudinal  Section. 

Fig.  122.— Masonry   Dam   unber   640-rooT  Head,  the  Geeatest  Recoeded 
Water  PRESSUEE  on  Masoney, 

nary  precedent  on  record  of  masonry  under  such  extremely  high  pressure. 
It  was  made  practically  water-tight  by  building  a  brick  wall,  22  inches 
thick,  26  inches  above  the  face  of  the  dam,  filling  the  intermediate  space 
with  concrete,  and  placing  a  quantity  of  horse-manure  against  the  brick- 
work, which  was  held  in  position  by  a  plank  partition  or  bulkhead.  When 
finally  tested  the  leakage  was  but  7  gallons  per  minute.  The  dam  cost 
$484.27.    (See  Engineering  News,  Dec.  16,  1897.) 

New  Croton  Dam,  New  York.— The  great  dam  in  process  of  erection 
for  increasing  the  water-supply  of  New  York  City  will,  when  completed,  be 


MASONRY  DAMS. 


237 


the  highest  as  well  as  the  most  costly  dam  in  America.  It  will  consist  of  a 
central  masonry  dam  730  feet  long,  290  feet  maximum  height;  a  masonry 
overflow- weir  about  1000  feet  long,  extending  up-stream  from  the  north 
end  of  the  masonry  dam;  and  an  earthen  dam  with  a  masonry  core-wall, 
about  440  feet  long,  continuing  the  masonry  dam  to  the  south  side  of  the 
valley.  The  three  sections  of  the  dam,  including  the  weir  and  core-wall, 
will  thus  form  a  continuous  masonry  wall  across  the  valley,  which  will  be 
abouu  1300  feet  long  on  top.  The  masonry  dam  proper  will  have  a  base 
width  of  185  feet  and  crest  width  of  18  feet,  exclusive  of  the  parapets  pro- 
tecting the  roadway.  The  extreme  height  of  the  dam  above  the  original 
stream-bed  is  to  be  163  feet.  The  crest  is  to  be  14  feet  higher  than  the  lip 
of  the  overflow-weir,  and  the  top  of  the  earth  dam  is  to  be  10  feet  higher 
than  the  masonry.  The  contract  for  construction  of  the  dam  was  let  to 
Jas.  S.  Coleman,  Aug.  31,  1892,  for  $4,152,573,  of  which  $2,876,000  had 
been  expended  for  work  done  to  January  1,  1899.  The  ultimate  cost  will 
largely  exceed  the  contract  price,  on  account  of  a  great  increase  of  depth 
beyond  the  original  expectations.  The  stone  is  handled  by  three  lines  of 
cableway  with  spans  of  1200  feet  between  supports,  and  by  30  steam- 
derricks  located  on  the  dam.  It  is  quarried  1|  miles  distant  and  brought 
to  the  work  by  a  narrow-gauge  railway,  on  which  7  locomotives  and  83  flat- 
cars  are  employed.  Thirteen  derricks  with  independent  steam  hoisting- 
engines  are  used  in  the  quarry.  The  volume  of  water  pumped  from  the 
excavations  to  and  into  the  bed-rock  has  not  exceeded  5,000,000  gallons 
daily.  This  volume,  compared  with  the  approximate  area  of  the  cross- 
section  of  the  valley  from  bed-rock  up  to  the  level  of  the  river-bed,  indi- 
cates a  maximum  movement  of  the  subterranean  water  down  the  valley  at 
the  rate  of  about  2|-  miles  per  annum,  assuming  that  none  of  the  water 
pumped  was  returning  to  the  pit  from  the  lower  side.  The  watershed  area 
above  the  dam  is  360.4  square  miles.  The  reservoir  when  full  will  sub- 
merge an  area  of  3360  acres.  The  plans  for  the  dam  were  designed  by 
Alphonse  Fteley,  Chief  Engineer  of  the  Aqueduct  Commission.  Construc- 
tion is  under  the  immediate  charge  of  Charles  S.  Gowen,  Division  Engineer, 
and  B.  S.  Value,  Assistant  Engineer. 

The  original  estimate  of  the  volume  of  masonry  of  all  kinds  required  in 
the  dam  was  about  579,000  cubic  yards,  of  which  the  greater  portion,  or 
470,000  yards,  was  to  be  rough  rubble  laid  in  American  (natural)  cement 
mortar,  the  remainder  to  be  laid  with  artificial  Portland  cement. 

The  Titicus  Dam,  New  York. — This  structure  is  a  part  of  the  system  of 
storage  for  the  supply  of  New  York  City,  and  was  built  in  1890  to  1895,  at 
a  cost  of  $933,065.  It  resembles  the  New  Croton  Dam  in  general  design, 
in  that  it  is  a  combination  of  masonry  and  earth,  the  higher  portion  in  the 
center  of  the  valley  consisting  of  masonry,  flanked  on  either  side  by  earthen 
embankments,  provided  with  a  central  core-wall  of  masonry.    The  main 


238         BE8ERV0IR8  FOR  IIUIIOATION,  WAT HJU- POWER,  ETC. 

nnsonry  dmu  is  135  feet  liigli  above  foundation,  100  feet         above  original 
sui-race;  75.2  feet  thick  at  the  level  of  the  stream-bed,  20.7  feet  thick  at  top, 
•ind  53-i  feet  long.    The  earthen  dams  are  732  and  253  feet  long,  respectively, 
Ihe  total  length  1)f  dam  being  1519  feet.    A  waste-weir,  200  feet  long,  built 
in  steps  on  the  lower  side,  is  carried  over  a  portion  of  the  mam  masonry 
dam     The  masonry  consists  of  rough  rubble,  faced  on  either  side  with  cut 
stone,  laid  in  regular  courses.    The  earthen  dam  is  9  feet  higher  than  the 
crest  'of  the  spillway.    It  is  30  feet  wide  on  top,  with  slopes  of  2^  to  1. 
The  core-wall  is  of  rubble  masonry,  5  feet  on  top  and  17  feet  thick  at  a 
depth  of  98  feet.    It  reaches  to  a  maximum  height  of  124  feet  above  base. 
The  greatest  depth  of  water  is  105  feet.    The  dam  was  planned  by  A. 
rteley.  Chief  Engineer,  and  construction  was  originally  in  charge  of  Charles 
S.  Gowen,  who  was  subsequently  succeeded  by  Alfred  Craven  as  Division 
Engineer,  and  M.  E.  Kidgwa;y,  Assistant  Engineer. 

The  Sodom  Dam,  New  York.— This  is  a  purely  masonry  structure,  built 
across  the  east  branch  of  the  Croton  Eiver  in  1888-93,  by  the  Aqueduct 
Commission  of  New  York,  and,  in  connection  with  the  Bog  Brook  dams  1 
and  2,  forms  what  is  known  as  -  Double  Reservoir  1."  The  reservoirs  were 
connected  by  a  tunnel,  1788  feet  long,  by  which  the  surplus  water  from  the 
Sodom  dam  is  made  to  supply  the  other  reservoir,  whose  watershed  was  but 
3  5  square  miles,  while  that  tributary  to  the  Sodom  reservoir  was  73.4  square 
miles  The  tunnel  thus  equalizes  the  supply  from  the  two  watersheds.  The 
combined  storage  capacity  of  the  two  reservoirs  is  about  9,500,000,000  gal- 
lons The  Sodom  dam  is  500  feet  long  on  top,  98  feet  high  above  founda- 
tion^  78  feet  above  stream-bed,  and  the  masonry  has  a  bottom  thickness  of 
53  feet,  and  is  12  feet  wide  at  top.  It  contains  35,887  cubic  yardsof  rubb  e 
masonry,  chiefly  laid  in  Portland-cement  mortar,  mixed  2  to  1  and  3  to  1. 
A  continuation  of  the  masonry  dam  is  carried  along  the  crest  of  the  ridge 
nearly  at  right  angles  to  the  wall,  in  the  form  of  an  earthen  embankment,  9 
feet  high,  600  feet  long.    In  extension  of  this  bank  is  a  masonry  overflow,  8 

feet  hiffh,  500  feet  long.  .  .  -r^  ■ 

The  cost  of  the  dam  was  $366,490.  It  was  planned  by  Chief  Engineer 
Fteley,  and  constructed  by  Geo.  B.  Bnrbank,  Diyision  Engineer,  and  Walter 
McCulloh,  Assistant,  later  Division  Engineer.  An  interesting  account  o 
the  dam  is  to  be  found  in  a  paper  prepared  for  the  American  Society  of  Civil 
Enc^ineers  in  March,  1893,  by  Mr.  MoCuUoh,  from  which  it  appears  to  be 
one  of  the  few  masonry  dams  that  were  quite  water-tight  from  the  first  filling 
of  the  reservoir,  although  "sweating"  appears  at  several  points  on  the  lower 
face  The  dam  was  built  by  the  aid  of  a  3-inch  cableway,  stretched  along 
its  axis,  with  a  span  of  667  feet  between  towers.  The  Sodom  reservoir 
covers  Ln  area  of  574.9  acres  and  impounds  4,883,000,000  ga  Ions.  The 
Boc'  Brook  reservoir,  with  which  it  is  connected,  floods  a  surface  area  of 
4in'.4  acres.    The  Bog  Brook  dams  are  of  earth  with  masonry  core.  Dam 


MASONRY  DAM8.  239 

No.  1  is  60  feet  high  and  holds  54  feet  maximum  depth  of  water.  It  is  25 
feet  wide  on  top.  The  core-wall  is  10  feet  thick  at  base,  6  feet  at  top.  Dam 
No  2  is  25  feet  high.    The  cost  of  the  two  dams  was  $510,430. 

The  Boyd's  Corner  Dam,  New  York.— In  1866  the  Croton  Aqueduct 
Board  of  New  York  began  a  masonry  dam  near  Boyd's  Corners,  on  the  west 
branch  of  Croton  River,  which  was  completed  in  1872.  The  dam  contams 
27  000  cubic  yards  of  masonry,  of  which  21,000  yards  are  concrete  hearting 
and  6000  yards  are  cut-stone  facings.  The  dam  has  a  maximum  height  of 
78  feet,  is  670  feet  long  on  top,  200  feet  long  at  level  of  stream-bed,  53.6 
feet  thick  at  base,  8.6  feet  at  top.  The  base  is  laid  with  a  batter  of  i  to  1 
on  each  side  to  the  original  stream-level,  60  feet  below  the  crest,  where  an 
offset  of  1.5  feet  was  made  on  each  side,  and  the  dam  was  then  carried  up 
vertically  on  the  water-face,  and  given  a  batter  of  0.4  to  1  on  the  lower  side. 
The  reservoir  covers  279  acres  and  impounds  2,722,700,000  gallons  of 

The  Indian  River  Dam,  New  York. -This  important  structure  was 
erected  in  1898  for  increasing  the  size  of  Indian  Lake  and  thus  store  water 
to  supply  the  Champlain  Canal,  to  add  to  the  water-power,  and  to  improve 
the  navigation  of  Hudson  River.    It  is  located  in  Hamilton  County  in  the 
northern  part  of  New  York  State,  on  a  tributary  of  the  Hudson,  at  an 
elevation  of  1655  feet  at  the  high-water  line.    The  dam  is  a  combination 
masonry  and  earth  structure,  straight  in  plan,  the  masonry  portion  being 
47  feet  in  extreme  height,  having  a  base  width  of  33  feet,  a  thickness  on 
crest  of  7  feet,  and  a  total  length  of  207  feet.    The  earth  embankment  is 
a  continuation  of  the  masonry,  200  feet  long,  15  feet  wide  on  top,  with 
inner  slopes  of  2i  to  1,  paved  with  12  inches  of  stone  riprap.    The  outer 
slope  is  2  to  1.    Through  the  center  is  a  core-wall  of  masonry,  4  feet  thick 
at  base,  2  feet  at  top,  reaching  to  within  2  feet  of  the  crest  of  the  embank- 
ment.   The  end  of  the  embankment  next  the  dam  is  supported  on  the 
down-stream  side  by  a  masonry  spur-wall  at  right  angles  to  the  dam.  The 
embankment  rests  on  hard-pan,  into  which  the  core- wall  is  carried  down 
uniformly  4  feet  thick  to  depths  of  8  to  20  feet,  filling  the  trench  cut 
for  it. 

On  the  opposite  or  west  end  of  the  dam  a  spillway  was  excavated  m 
granite,  having  an  effective  length  of  106.5  feet  and  a  depth  of  6  feet,  to 
the  bottom  of  the  floor-stringers  of  the  foot-bridge  which  spans  it  and 
which  rests  on  five  masonry  piers.  The  capacity  of  discharge  is  estimated  at 
5000  second-feet.  The  coping  is  made  of  large,  selected  stones  firmly 
doweled  to  the  masonry.  A  logway,  15  feet  wide,  whose  crest  is  17  feet 
below  the  top  of  the  dam,  is  provided  through  the  masonry.  It  is  closed 
with  45  wooden  needles,  4''  X  8",  20  feet  long,  which  are  handled  by  block 
and  tackle.  The  outlets  to  the  reservoir  consist  of  two  50-inch  steel  pipes, 
controlled  by  Eddy  flume-gates,  and  having  a  discharging  capacity  of  1500 
second-feet  with  full  reservoir.    The  gates  are  inside  of  a  tower,  on  the 


2-1:0         llESmVOIRS  FOR  initio ATION,  WATElt-POWKR,  ETC. 


exterior  of  wliicli  are  auxiliary  sluice-gates  of  wood,  raised  by  screws.  A 
0-incli  by-pass  pipe  enters  tlie  tower  from  tlie  reservoir,  by  which  the  tower 
is  filled  and  the  pressure  relieved  from  the  wooden  gates,  so  that  they  can 
be  readily  raised. 

The  total  actual  cost  of  the  work,  including  $13,000  for  clearing,  was 
$83,555,  the  contract  price  being  $92,000.  Under  the  most  favorable  con- 
ditions the  cost  per  cubic  yard  for  the  masonry  was  as  follows: 


Cement   $2.00 

Sand.  15 

Quarrying  stone  35 

Labor  of  laying  masonry  53 

Labor  of  pointing  masonry  15 

Labor  of  mixing  mortar,  concrete,  and  crushing  20 

General  expenses,  superintendence,  etc  27 


Total   $3.65 


The  cement  used  was  made  at  Glenn's  Falls,  N.  Y.,  of  the  ''Ironclad'' 
brand  of  artificial  Portland. 

The  reservoir  formed  by  the  dam  has  a  storage  capacity  of  4,468,000,000 
cubic  feet,  or  102,548  acre-feet,  and  floods  an  area  of  5035  acres.  The 
original  lake  covered  1000  acres,  and  the  new  dam  raised  the  mean  surface 
of  the  lake  33  to  34  feet.  The  tributary  drainage-area  above  the  dam  is 
146  square  miles,  the  run-off  from  which  can  be  safely  estimated  to  fill  the 
reservoir  every  year. 

The  dam  was  built  for  the  Forest  Preserve  Board  of  New  York  State  by 
the  Indian  Eiver  Company.  It  was  planned  by  Geo.  W.  Rafter,  M.  Am. 
Soc.  C.  E.,  and  constructed  under  his  supervision  by  Wallace  Greenalch, 
Jun.  Am.  Soc.  C.  E.,  as  Assistant  Engineer. 

For  further  details  of  this  interesting  work  the  reader  is  referred  to  En- 
gineering Neius  of  May  18,  1899,  containing  descriptive  illustrated  papers  on 
the  subject  by  Messrs.  Rafter  and  Greenalch. 

Cornell  University  Dam,  New  York. — In  1897  an  overflow  masonry  dam 
was  built  across  Fall  Creek  near  Ithaca,  N.  Y.,  as  a  portion  of  the  hydraulic 
laboratory  plant  of  Cornell  University.  It  is  curved  in  plan  on  a  radius  of 
166.5  feet,  and  is  153  feet  long  on  top,  with  a  maximum  height  of  30  feet, 
and  a  gravity  section,  vertical  up-stream,  and  stepped  on  the  lower  face.  It 
is  located  at  the  head  of  Triphammer  Falls,  in  a  picturesque  gorge,  cut 
deeply  into  the  shale  formation  of  that  region,  where  the  total  fall  is  about 
400  feet  in  a  mile.  The  stream  drains  a  watershed  of  117  square  miles,  on 
which  the  mean  precipitation  from  1880  to  1897  was  35.22  inches.  The 
mean  flow  is  about  175  second-feet,  ranging  from  a  minimum  of  12  to  a 
maximum  of  4800  second-feet.  In  times  of  flood  the  water  discharges  over 
the  crest  of  the  dam  and  over  a  natural  spillway  ledge  at  one  end  of  the 
dam,  a  total  width  of  267.5  feet,  made  up  of  134.5  feet  on  the  dam  and  133 
feet  on  the  natural  spillway. 


MASONRY  DAMS. 


24:1 


The  dam  is  of  gravity  section,  and  made  of  concrete,  composed  of  four 
parts  of  hard,  clean,  argillaceous  shale,  two  parts  of  sand,  and  one  part  of 
*'  Improved  cement/'  The  Improved  cement"  is  a  mixture  of  Eosendale 
and  artificial  Portland  in  the  proportion  of  weight  of.  3  to  1,  ground  together 
in  the  clinker  state,  and  costiug  one- half  the  cost  of  pure  Portland  cement. 

One  of  the  interesting  and  unusual  features  of  the  construction  of  this 
dam  was  the  provision  made  for  concentrating  the  contraction  due  to  tem- 
perature changes  in  the  concrete  to  a  central  point  of  weakness.  This  was 
done  by  leaving  a  5-f  t.  circular  opening  through  the  dam  during  construc- 
tion, connecting  with  which  was  an  open  well  extending  up  through  the 
heart  of  the  dam  to  its  crest.  At  this  point  the  section  was  thus  reduced 
to  60^  of  the  normal,  and  shortly  after  completion  the  wall  cracked  for  one- 
half  its  height  down  through  the  well.  During  unusually  cold  weather, 
when  the  crack  was  widest,  the  opening  through  the  dam  and  the  well  were 
filled  with  concrete,  and  the  contraction-crack  was  thus  effectually  closed. 

The  dam  and  other  works  connected  with  the  entire  plant  designated  as 
the  hydraulic  laboratory  were  designed  by  Prof.  E.  A.  Fuertes,  M.  Am. 
Soc.  C.  E.,  Director  of  the  College  of  Civil  Engineering.  Construction 
•was  in  charge  of  Mr.  Elon  H.  Hooker,  Eesident  Engineer.  Mr.  Ira  A. 
Shaler,  M.  Am.  Soc.  C.  E.,  was  contractor  for  the  work.  A  full  descrip- 
tion of  the  laboratory  is  given  in  Engineering  News,  March  2,  1899. 

The  Bridgeport  Dam,  Connecticut. — The  town  of  Bridgeport,  Conn., 
having  a  population  in  1890  of  48,890,  is  supplied  by  a  number  of  storage- 
reservoirs,  one  of  which  is  formed  by  a  masonry  dam  across  Mill  River,  built 
in  1886.    Its  general  dimensions  are  as  follows  : 


Maximum  height   42.5  feet. 

Bottom  thickness   32.0  " 

Top  thickness   8.0  -'^ 

Length  at  crest   640  " 

Length  at  base   50  " 


The  structure  is  composed  of  rubble  masonry  built  of  gneiss  rock  laid  in 
a  mortar  of  Eosendale  cement  and  sand  in  the  proportion  of  1  to  2.  The 
lower  face  of  the  dam  is  built  in  steps.  The  outlet  from  the  gate-chamber 
is  a  30-inch  cast-iron  pipe,  controlled  by  a  gate-valve  in  the  chamber.  The 
latter  structure  is  built  against  the  dam,  is  10  X  15  feet  inside,  in  two  com- 
partments, between  which  a  fish-screen  is  placed.  Three  30-inch  openings, 
at  different  levels,  controlled  by  gates,  lead  from  the  reservoir  to  the  outer 
compartment.  The  spillway,  at  one  end  of  the  dam,  is  80  feet  long,  5  feet 
deep.  The  reservoir  covers  60  acres  and  has  a  capacity  of  240,000,000  gal- 
lons (737  acre-feet).  The  dam  has  leaked  so  much  as  to  require  an  earth 
backing.* 


*  "The  Design  and  Construction  of  Dams,  'by  Edward  Wegmaun,  p.  85. 


242         llESEliVOlRS  FOli  IRliiaATlON,   WATER-POWER,  ETC. 


The  Wigwam  Dam,  Connecticut. — Tlie  city  of  Wiiterbury,  Conu.  (pop. 
28,(i-l:G  in  1890),  constructed  a  masonry  dam  in  1893-04  to  store  water  in  a 
reservoir  located  on  West  Mountain  Brook  and  receiving  the  drainage  from  18 
square  miles  of  watershed.  The  dam  was  designed  and  built  by  Eobt.  A 
Cairns,  City  Engineer.  It  was  planned  for  an  ultimate  height  of  90  feet,  at 
whicli  its  full  length  on  top  will  be  600  feet,  and  it  was  completed  ,with  full 
section  to  within  15  feet  of  the  ultimate  crest,  and  there  stopped,  as  the 
storage  at  that  level  was  sufficient  for  present  needs.  The  base  thickness  is 
02.08  feet,  and  it  is  12  feet  thick  on  the  crest.  The  cubic  contents  of  the 
completed  portion  are  14,887  cubic  yards,  of  which  5754  yards  are  laid  in 
Eosendale  cement,  and  the  remainder  in  American  Portland  cement  mortar. 
The  cost  has  been  $150,000.  The  present  capacity  of  reservoir  is 
335,000,000  gallons  (1028  acre-feet),  which  will  be  increased  to  714,000,000 
gallons  when  the  dam  is  completed.  A  temporary  wasteway,  82  feet  long, 
2  feet  deep,  has  been  made  at  one  end  of  the  dam,  which  is  of  insufficient 
capacity.  The  completed  dam  will  have  a  wastev/ay  100  feet  long  over  a 
rocky  ridge  some  distance  away,  and  another  78  feet  long  at  the  dam.  An 
earth  embankment  is  required  to  close  a  gap  in  the  reservoir,  as  an  auxiliary 
to  the  masonry  dam.  This  will  be  35  feet  high  when  finished,  but  is  built 
only  to  a  height  of  20  feet. 

The  Austin  Dam,  Texas. — The  city  of  Austin,  Texas,  the  capital  of  the 
State,  with  a  population  of  about  25,000  inhabitants,  has  erected  one  of 
the  most  notable  masonry  dams  of  the  United  States,  across  the  Colorado 
Eiver,  2^  miles  above  the  city,  for  power-development  purposes.  The  dam, 
Fig.  123,  was  built  in  1891-92.  It  was  designed  by  Mr.  Jos.  P.  Prizell, 
M.  Am.  Soc.  C.  E.  of  Boston,  and  about  two-thirds  completed  by  him.  He 
was  succeeded  by  Mr.  J.  T.  Panning.  The  dam  proper  is  1091  feet  long 
between  bulkheads  and  68  feet  high.  It  is  vertical  on  the  up-stream  face, 
while  the  down-stream  face  is  inclined  at  a  batter  of  3  in  8,  terminating  in 
a  vertical  curve  of  31  feet  radius,  while  the  crest  is  rounded  on  a  radius 
of  20  feet  on  lower  side,  forming  an  ogee  curve  that  has  the  general  shape 
of  the  trajectory  of  falling  water. 

Mr.  Prizell's  original  design  contemplated  a  flat  top  for  the  purpose  of 
facilitating  the  erection  on  the  crest  of  a  series  of  movable  flashboards, 
or  some  other  form  of  falling  dam,  that  could  be  lowered  in  flood-time,  but 
would  permit  of  increased  storage  during  low  seasons,  and  the  development 
of  a  more  uniform  volume  of  power  at  low  and  high  water. 

The  power  is  used  for  pumping  water  for  city  supply,  for  electric 
lighting,  propulsion  of  street  cars,  and  general  manufacturing.  Its  volume 
is  estimated  at  14,636  horse-power  for  60  working  hours  weekly. 

The  dam  is  straight  in  plan,  and  contains  about  88,000  cubic  yards  of 
masonry,  of  which  70,000  yards  aro  of  rough  rubble,  made  of  the  limestone 
quarried  near  the  site,  and  18,000  yards  are  of  cut-stone  range- work,  in 


LIBRARY 
Of-  THE 
<»NIV£RSITY  of  lLLINOk 


MASONRY  DAMS. 


245 


which  Burnett  County  blue  granite  was  used,  brought  a  distance  of  80  miles. 
The  entire  work  was  done  by  contract,  at  a  cost  of  $11  to  $15  per  yard  for 
the  cut-stone  masonry,  and  13.60  to  14.10  per  yard  for  the  rubble,  the 
larger  sum  being  for  work  in  which  Portland  cement  was  required.  The 
cost  of  the  dam  and  head-gate  masonry  was  1608,000,  and  the  entire 
expenditure,  including  dam,  power-house,  reservoir  and  distributing  sys- 
tem, lighting-plant,  etc.,  was  $1,400,000,  for  which  amount  the  city  voted 
its  bonds  May  5,  1890. 


l^^iG.  123a.— Austin  Dam  during  Flood  of  April  7,  1900,  and  Immediately 

BEFORE  THE  BrEAK. 


The  dam  is  founded  on  limestone  rock  throughout,  the  river  here 
flowing  through  a  gorge  with  cliffs  rising  from  70  to  125  feet  in  height 
above  the  river.  Lidgerwood  cableways  were  employed  in  placing  the  stone 
and  for  hauling  all  materials. 

The  Colorado  River  at  Austin  drains  an  area  of  40,000  square  miles, 
from  which  the  discharge  has  a  range  of  from  200  to  250,000  second-feet. 

The  reservoir  formed  by  the  dam  is  very  long  and  narrow,  extending 
back  19  to  23  miles  up  the  river  and  having  an  average  width  of  but  800 
feet.  Its  surface  area  is  1836  acres,  and  the  capacity  at  the  time  the  dam 
was  finished  was  53,490  acre-feet,  the  mean  depth  being  29.1  feet,  or  42.5% 


24(i        UKSKKVUIIIS  FOK  JUIUUATJOJV,  WATjeii-POWJUM.  ETC. 

of  tlio  lunxiimun.    The  Uam  was  completed  in  May,  1893,  and  the  water 
Jirst  overllowed  the  crest  of  the  dam  on  the  lUth  o£  tliat  month. 

Foxa-  years  siiksequeiitly,  in  May,  1897,  l>roI.  Thomas  U.  Tayh,r,  ol'  the 
University  of  Texas  at  Austin,  made  accurate  soundings  of  tlie  lake  to 
determine  the  volume  of  silt  which  had  accumulated  in  four  years,  and 
ascertained  that  the  deposit  amounted  to  968,000,000  cubic  feet  (23,237 
acre-feet),  or  U.hifo  of  the  original  capacity.   The  greatest  depth  of  fill 
was  at  the  dam,  33  feet;  three  miles  above  it  was  16.5  feet  deep  at  the 
maximum;  seven  miles  above,  20  feet;  9.3  miles  above,  21.3  feet;  14.6 
miles  above,  15.3  feet;  15.9  miles  above,  6.6  feet.  To  this  point  the  fiUmg 
was  composed  of  mud.   Above  this  distance  the  deposit  was  mostly  sand. 
Considering  the  total  volume  of  water  which  must  have  passed  through 
the  reservoir  during  the  four  years,  the  percentage  of  silt  deposited  seema 
very  small,  and  the  result  is  not  such  as  to  discourage  the  construction  of 
reservoirs  on  streams  where  the  ratio  between  run-off  and  storage  capacity 
is  less  disproportionate.   There  are  no  definite  data  available  of  the  total 
discharge  of  the  river,  but  assuming  it  to  have  been  about  50  acre-leet 
annually  per  square  mile  of  watershed,  which  is  a  reasonable  assumption 
for  streams  of  that  class  (the  run-off  of  New  York  and  New  England 
streams  is  from  700  to  2000  acre-feet  per  square  mile,  while  tdiat  of  the 
Bio  Grande  and  Gila  rivers  is  25  to  35  acre-feet  per  square  mile),  the  total 
volume  of  water  discharged  in  the  four  years  must  have  been  approximately 
8,000,000  acre-feet,  or  about  160  times  the  reservoir  capacity    The  rela- 
tion ^f  the  silt  deposited  to  total  run-off  would  be  m  the  ratio  of  about 
ne-fourth  of  one  per  cent  of  this  volume,  or  3770  ^^^^ 
The  river  Po,*  as  determined  by  M.  Tadmi,  carried  as  the  mean  of  four 
months  3333  'cubic  feet  per  million;  the  river  Ganges      «  as  he  mean 
13  months,  and  in  flood  12,300;  the  Mississippi  291  to       3'  ttie  river 
Indus  in  flood  2100.  'A  stream  of  the  size  and  character  of  the  Colorado 
Eiver  of  Texas,  to  be  utilized  for  irrigation  should  have  a  reservoir^  o 
onl  L  two  million  acre-feet  capacity,  to  he  in  proper  proportion  to  the 
volume  of  run-off  and  amount  of  silt  carried,  and  mamtam  a  -ffic-nt  y 
longTerLd  of  usefulness  to  be  profitable.  Such  a  reservoir  would  probably 
not  he  filled  with  silt  short  of  400  to  500  years. 

Fa^reof  Austin  Bam.-On  the  7th  of  April,  1900,  a  severe  flood 
in  tL  Co  rado  Kver  and  its  tributaries,  unprecedented  since  the  erection 
of  the  dam,  resulted  in  the  failure  of  this  fine  structure,  -th -nsiderable 
los  oi  life  About  500  feet  of  the  masonry  was  first  pushed  bodily  down- 
t  al  about  60  feet,  apparently  sliding  on  its  ba.e,  and  af^r  a  few  hour 
was  entirely  broken  up  and  washed  away,  with  the  exception  of  a  small 
retion!  which  still  stands  upright  in  the  positio^^here^Wasfe-st^ 


Fig.  128c.— Austin  Da:.i,  Texas,  aftfjj  Subsidence  op  Flood  of  April  1,  1900. 
Showing  section  of  masonry  moved  bodily  down-stream. 


01-  THE 
ilNJVERSITVoflLLINOli 


Ot  THE 
UNIVERSITY  of  ILUNOli 


MASONRY  DAMS. 


251 


posited.  Measured  along  the'crest^  the  break  left  about  500  feet  of  the 
dam  at  the  west  end  and  83  feet  at  the  east  end  still  unaffected.  About 
two-thirds  of  the  wall  of  the  power-house  below  the  dam  next  the  river 
was  also  destroyed  by  the  flood.  The  entire  property  loss  must  have  ex- 
ceeded $500,000.  At  the  time  of  the  break  the  lake-level  had  reached  a 
height  of  11.07  feet  above  the  crest.  The  flood  was  the  result  of  extraor- 
dinary rains  throughout  a  very  extensive  watershed  area.  In  fifteen  hours 
the  rainfall  at  Austin  and  vicinity  was  5  inches,  falling  on  ground  already 
well  soaked  by  previous  rains.  The  maximum  flood  prior  to  the  catastrophe 
occurred  June  7,  1899,  when  the  water  rose  to  9.8  feet  above  the  crest  of 
the  dam,  without  injury  to  the  structure.  The  dam  will  probably  be  rebuilt 
upon  safer  plans,  and  precautions  taken  to  anchor  it  into  bed-rock  a  suf- 
ficient depth  to  prevent  it  from  sliding  on  its  foundations. 

The  appearance  of  the  dam  immediately  before  the  break  is  shown  in 
rig.  123a.  Figs.  123&  and  123c  graphically  present  the  break  and  the 
bodily  movement  of  a  section  of  the  dam  down-stream  intact,  better  than 
any  detailed  description.  The  author  is  indebted  to  Engineering  News  for 
these  three  cuts. 

Mexican  Dams. — By  courtesy  of  Modern  Mexico,  of  St.  Louis,  Mo.,  the 
accompanying  views  of  two  notable  masonry  dams  at  Guanajuato,  Mexico, 
are  incorporated  in  this  work,  as  types  of  reservoir  construction  in  our 
neighboring  republic.  Fig.  124  shows  the  upper  dam,  from  which  water 
is  supplied  to  the  higher  portion  of  the  city,  through  a  stand-pipe  that  is 
shown  in  the  view  of  the  lower  dam,  or  the  "  Presa  de  la  Olla,^'  Fig.  125 
(frotispiece). 

The  upper  dam  is  evidently  a  massive,  ornate  structure  that  would  do 
credit  to  any  country  of  the  world,  as  far  as  exterior  appearances  can 
lead  one  to  judge,  although  the  precise  dimensions  are  unfortunately  lack- 
ing. Estimating  from  the  proportions  of  the  figures  in  the  foreground, 
the  height  of  the  dam  must  be  at  least  80  feet. 

The  view  of  the  lower  dam  was  taken  on  St.  John's  Day,  the  24th  of 
June,  which  is  celebrated  annually  by  a  function  called  the  "  Fiesta  de  la 
Presa,"  or  the  feast-day  of  the  dam. 

Sharply  at  12  o'clock,  noon,  of  that  day,  the  people  congregate  to 
witness  the  opening  of  the  gates,  bringing  refreshments  and  musical  in- 
struments for  a  picnic,  and  thus  commences  a  fortnight  of  gayety, 
gambling,  bull-fights,  cock-fio;hts,  theater,  and  dancing.  The  object  of 
letting  out  the  water  is  to  clear  the  reservoir  preparatory  to  the  advent 
of  the  rainy  season,  which  usually  begins  about  that  day. 

The  water  thus  released  washes  out  the  river-bed  below,  which  is  the 
main  drainage  of  the  city. 


252 


IIESERVOIRS  FOR  IlUilGATlON,  WATER-POWER,  ETC. 


FoiiEiCN  Dams. 

The  following  descriptions  of  the  principal  masonry  dams  of  the  world 
outside  of  the  United  States  have  been  condensed  from  the  valuable  work 
on  "The  Design  and  Construction  of  Dams/'  by  Edward  Wegmann, 
M.  Am.  Soc.  C.  E.,  published  in  1899. 

The  Almanza  Dam,  Spain.— The  oldest  existing  masonry  dam  was 
erected  in  the  Spanish  province  of  Albacete  prior  to  158G.  It  is  built  of 
rubble  masonry,  faced  with  cut  stone,  and  is  67.8  feet  high,  33.7  feet  thick 
at  base,  and  of  the  same  thickness  for  23.5  feet  of  its  height,  the  upper  side 
being  vertical,  and  the  lower  face  stepped.  The  crest  is  9.84  feet  thick. 
The  lower  48  feet  is  built  on  curved  plan  with  radius  of  86  feet.  The 
upper  portion  is  irregular.  The  maximum  pressure  upon  the  masonry  is 
14.33  tons  per  square  foot. 

The  Alicante  Dam,  Spain.— This  structure,  erected  in  a  narrow  gorge 
on  the  river  Monegre,  in  1579  to  1594,  is  the  highest  dam  in  Spain,  and 
is  used  for  irrigation  of  the  plains  of  Alicante.  The  height  is  134.5  feet, 
the  base  width  being  110.5  feet,  and  the  crest  65.6  feet.  The  gorge 
is  remarkably  narrow,  being  but  30  feet  at  bottom  and  190  feet  at  the  top 
of  the  dam.  The  dam  is  curved  in  plan,  with  a  radius  of  351.37  feet  on  the 
up-stream  face  at  crest,  which  has  a  batter  of  3  to  41.  The  dam  is  built 
of  rubble  masonry,  faced  with  cut  stone.  It  is  supposed  to  have  been 
designed  by  Herreras,  the  famous  architect  of  the  Escurial  palace. 

The  reservoir  formed  by  the  dam  is  small  for  so  large  a  structure, 
having  a  length  of  but  5900  feet  and  a  capacity  of  975,000,000  gallons 
(2982  acre-feet). 

The  stream  carries  such  a  large  volume  of  silt  that  it  is  necessary  to 
scour  out  the  sediment  by  a  device  called  a  scouring-gallery.  The  scouring 
is  done  every  four  years.  The  gallery  is  a  culvert  through  the  center  of  the 
dam  at  the  bottom,  5.9  feet  wide,  8.86  feet  high  at  the  upper  end,  and  en- 
larged below.  The  mouth  is  closed  by  a  timber  bulkhead,  which  is  cut  out 
from  below  when  the  scouring  is  to  be  done.  The  sediment  forms  to  a 
great  depth  above  the  mouth  of  the  culvert,  and  has  to  be  started  to  move 
by  punching  a  hole  through  it  with  a  heavy  iron  bar.  The  total  cost  of 
scouring  the  reservoir  amounts  to  $50.  The  sediment  which  is  not  swept 
out  by  the  velocity  of  the  current  is  shoveled  into  the  stream  by  workmen. 

The  Elche  Dam,  Spain. — This  structure  has  a  maximum  height  of  76.1 
feet  and  a  base  of  39.4  feet,  and  is  formed  in  three  parts,  closing  converging 
valleys.  The  principal  wall  is  230  feet  long  and  built  of  rubble  faced  with 
cut  stone.  It  is  curved  in  plan,  up-stream,  with  a  radius  of  205.38  feet. 
It  is  provided  with  a  scour^ing-sluice  similar  to  that  at  the  Alicante  dam, 
but  so  designed  as  to  be  safer  for  the  workmen  who  remove  the  timbers 


MASONRY  DAMS. 


253 


forming  the  bulkhead  at  the  mouth  of  the  sluice.  The  dam  is  located  near 
the  town  of  Elche,  on  the  Kio  Vinolapo. 

The  Puentes  Dam,  Spain. — This  structure  is  noted  because  it  was  of 
unusual  height  and  massiveness,  and  yet  failed  by  reason  of  its  having 
been  founded  on  piles  driven  into  a  bed  of  alluvial  soil  and  sand  instead 
of  bed-rock.  It  was  erected  in  1785  to  1791,  on  the  Guadalantin  River, 
at  the  junction  of  three  tributary  streams,  and  stood  successfully  for  eleven 
years,  during  which  time  the  depth  of  water  never  exceeded  82  feet,  but 
in  1802  a  flood  occurred  which  accumulated  a  depth  of  154  feet  in  the 
reservoir,  and  produced  sufficient  pressure  to  force  water  through  the 
earth  foundation.  The  reservoir  was  emptied  in  an  hour,  the  pipe  founda- 
tion was  washed  out,  and  a  breach  in  the  masonry,  56  feet  wide,  108  feet 
high,  was  created,  destroying  the  dam  and  leaving  a  bridge  arching  over 
the  cavity.  The  extreme  height  of  the  dam  was  161  feet,  and  its  crest 
length  was  925  feet;  its  thickness  at  base  was  115.3  feet,  and  at  top  35.72 
feet.  The  extreme  pressure  on  the  masonry  was  computed  by  M.  Aymard 
at  8.12  tons  per  square  foot.  It  was  built  of  rubble  masonry,  with  cut-stone 
facings,  and  was  polygonal  in  plan,  with  convexity  up-stream.  Water  was 
taken  from  it  through  two  culverts,  one  near  the  base,  and  the  other  100 
feet  from  the  top.  These  were  5.4  feet  wide,  6.4  feet  high,  and  connected 
with  masonry  wells  having  small  inlet-openings  from  the  reservoir.  A 
scouring-sluice,  22  feet  wide,  24.7  feet  high,  was  also  provided  through  the 
dam,  divided  by  a  pier  into  two  openings  at  its  mouth  to  shorten  the  span 
of  the  timbers  that  closed  it.  At  the  time  of  the  break  the  mud  deposited 
in  the  reservoir  was  44  feet  deep. 

The  disaster  caused  the  loss  of  608  lives  and  the  destruction  of  809' 
houses.    The  property  loss  was  estimated  at  $1,045,000. 

The  dam  is  reported  to  have  been  recently  restored,  and  was  doubtless 
extended  to  bed-rock  for  its  foundation. 

Val  de  Infierno  Dam,  Spain. — This  dam  is  116.5  feet  high,  and  founded 
on  rock.  It  has  an  enormous  section,  the  base  width  being  137  feet.  Even 
within  15  feet  of  the  top  the  thickness  of  the  wall  is  over  97  feet.  It  was 
built  for  irrigation  in  1785  to  1791,  and  is  located  on  one  of  the  branches 
of  the  Guadalantin  Elver,  above  the  Puentes  dam.  It  is  not  now  in  service^ 
and  the  reservoir  has  entirely  filled  with  sediment.  The  scouring  of  the 
silt  from  the  reservoir  injured  the  property  below,  which  led  to  the  aban- 
donment of  the  structure. 

The  scouring-sluice  of  the  dam  is  14.8  feet  high,  9  to  12.3  feet  wide. 

The  Nijar  Dam,  Spain. — This  dam  has  a  maximum  height  of  101.5  feet 
above  the  bed  of  the  stream,  and  consists  of  a  massive  base  of  masonry, 
144  feet  thick,  70  feet  high.  On  this  the  dam  proper  rests,  having  a  base 
thickness  of  67.6  feet.  The  upper  face  is  vertical,  and  the  down-stream 
face  is  built  in  high  steps.    The  scouring-sluice,  which  is  an  appendage 


I 


254:         llESEUVOIRS  FOR  IIlliTOATION,  WATER-POWER,  ETC. 

oi"  all  Spanish  dams,  is  3.3  I'eet  wide  b.y  7.2  i'eei  high,  ch)se(l  at  its  upper 
end  by  a  gate  operated  by  a  long  rod  extending  to  the  top  of  the  dam.  The 
reservoir  capacity  formed  by  the  dam  is  12,570  acre-feet. 

The  Lozoya  Dam,  Spain.— The  object  of  this  structure,  which  was  built 
about  1850  across  the  llio  Lozoya,  was  not  to  store  water,  but  simply  as  a 
diversion-weir  to  supply  a  canal  leading  to  the  city  of  Madrid.  Its  height 
is  105  feet,  top  length  237.8  feet,  and  it  consists  of  a  wall  of  cut  stone, 
straight  m  plan,  having  a  thickness  of  128  feet  at  base,  backed  up  partially 
by  a  sloping  bank  of  gravel.  The  canal  is  taken  through  a  tunnel  m  the 
rock  on  the  right  bank,  22.4  feet  below  the  top.  A  second  tunnel,  used 
as  a  scouring-sluice,  is  placed  7.5  feet  lower  than  the  canal,  below  which 
the  reservoir  is  allowed  to  fill  with  sediment.  A  waste-weir  is  cut  in  the 
rock,  on  the  left  bank,  11  feet  deep,  27.6  feet  wide. 

The  Villar  Dam,  Spain.-^In  1870-78  the  Spanish  Government  con- 
structed a  second  dam  on  the  Eio  Lozoya,  to  supplement  the  supply  to 
Madrid  by  storage.  The  dam  is  170  feet  high,  547  feet  long  on  top,  154.6 
feet  thick  at  base,  14.75  feet  thick  at  the  crest,  which  is  8.25  feet  above 
the  spillway  level.  The  dam  is  modern  in  design,  and  has  a  gravity  profile 
with  large  factor  of  safety.  It  is  also  curved  in  plan,  on  a  radius  of  440 
feet  It  is  constructed  of  rubble  masonry  throughout,  with  the  exception 
of  cut-stone  copings.  Its  cost  was  about  $390,000.  The  capacity  of  the 
reservoir  formed  by  it  is  13,050  acre-feet.  Two  scouring-sluices  are  built 
through  the  dam  and  closed  by  gates  that  are  operated  by  hydraulic  power 
from  a  central  tower. 

The  Hijar  Dams,  Spain.— Water  is  stored  for  irrigation  on  the  Martm 
Eiver,  above  the  city  of  Hijar,  Spain,  by  means  of  two  masonry  dams  built 
in  1880.  The  general  dimensions  of  each  of  these  dams  are  'about  alike, 
the  height  being  141  feet,  length  236  feet  on  top,  thickness  at  base  147  feet, 
and  at  crest  16.4  feet.  The  water-face  is  vertical  for  82  feet  from  the  top, 
continuing  with  a  vertical  curve  to  the  base.  The  outer  face  is  in  a  series 
of  steps  below  a  point  29.5  feet  from  the  top,  each  step  being  6.D 
feet  high,  4.9  feet  wide.   Both  dams  are  arched  up-stream  with  a  radius  ot 

210  feet.  ^        .     1  , 

One  of  the  reservoirs  has  a  capacity  of  8913  acre-feet,  and  a  watershed 
of  17  square  miles;  the  other  impounds  4864  acre-feet,  and  receives  the 
drainage  from  92  square  mdes.  .  .  .  ^ 

The  Gros-Bois  Dam,  France.— This  structure  has  been  severely  criticised 
because  of  the  fact  that  it  would  be  more  stable  to  resist  water-pressure 
applied  from  the  lower  side  than  the  upper,  and  for  the  reason  that  it 
lias  an  excess  of  masonry  over  what  would  be  required  if  it  were  distributed 
in  proper  form;  and  yet  it  has  but  a  small  factor  of  safety,  as  was  proven 
by  the  fact  that  it  slid  down-stream  on  its  base  about  2  inches,  and  was 
only  relieved  of  strains  that  produced  cracks  and  leaks  by  the  addition 


MASONRY  DAMS. 


255 


of  nine  counterforts^  13  to  37  feet  thick,  projecting  26  feet  from  the  base. 
The  dam  was  originally  built  vertical  on  the  down-stream  face,  and  stepped 
on  the  waterside.  Its  height  above  bed  is  73.2  feet,  extreme  height  92.9 
feet;  top  length  1804.6  feet;  thickness  at  base  45.9  feet,  at  top  21.32  feet. 
It  is  founded  on  argillaceous  rock,  rather  soft.  The  dam  was  built  in 
1830-38,  on  the  Brenne  Eiver,  for  feeding  the  navigable  canal  of  Bour- 
gogne. 

The  Chazilly  Dam  was  constructed  after  the  general  type  of  the  Gros- 
Bois  dam,  and  on  the  same  profile.  It  is  on  the  Sabine  Eiver,  near  the  city 
of  Chazilly,  and  is  1758.6  feet  long,  73.8  feet  high,  53  feet  thick  at  base, 
13.4  feet  at  crest. 

The  Zola  Dam,  designed  by  the  father  of  the  noted  novelist,  is  one  of 
the  few  dams  depending  solely  upon  their  arched  form  for  their  stability. 
It  is  119.7  feet  high,  48.8  feet  thick  at  base,  19  feet  thick  at  top,  and  205 
feet  long  on  the  crest,  which  is  surmounted  by  a  parapet  4  feet  high.  The 
gorge  has  a  width  of  but  23  feet  at  the  base  of  the  dam.  The  radius  of 
the  arch  is  158  feet  at  the  crown.  The  water-face  has  three  steps  or  offsets 
from  the  vertical  and  the  profile  is  quite  erratic  and  irregular.  It  forms  a 
reservoir  for  supplying  the  city  of  Aix  with  water,  and  was  built  about  the 
year  1843.   It  is  made  of  rubble  masonry,  founded  on  rock. 

The  Furens  Dam. — Among  many  engineers  this  famous  dam  is  recog- 
nized as  a  model  of  correct  form,  profile,  and  dimensions,  whose  outlines 
•conform  closely  to  what  are  accepted  as  certainly  safe  and  well-balanced 
proportions  throughout,  even  though  the  volume  of  material  may  be 
slightly  excessive.  It  was  built  by  the  French  Government  in  1862  to  1866 
for  the  purpose  of  controlling  the  floods  of  the  Furens  Eiver  and  protecting 
the  town  of  St.  Etienne  from  inundations. 

The  dam  is  183.7  feet  in  extreme  height  on  the  down-stream  side,  170.6 
feet  in  height  on  the  up-stream  side,  and  carrying  a  maximum  depth  of  164 
feet  of  water.  Its  base  thickness  is  165.8  feet,  and  it  is  16.4  feet  thick  at 
a  depth  of  21  feet  below  the  top.  The  crest  is  12.4  feet  wide,  and  is  used 
as  a  carriage-road;  the  top  length  is  326  feet.  The  dam  was  four  years  in 
building,  construction  being  limited  to  six  moilths  each  season,  owing  to 
the  altitude  and  to  the  severity  of  the  winter  weather.  Each  year,  while 
building,  the  water  was  allowed  to  flow  over  the  top  of  the  finished  masonry, 
and  when  completed  no  leakage  was  visible  further  than  a  few  damp  spots 
on  the  lower  side  with  full  reservoir. 

The  dam  contains  52,300  cubic  yards  of  masonry,  and  cost  $318,000, 
of  which  the  city  of  St.  Etienne  paid  $190,000  for  the  privilege  of  the 
storage  for  its  domestic  supply.  The  rock  used  was  mica-schist.  Notwith- 
standing its  safe  gravity  profile  the  dam  was  curved  up-stream,  with  a 
radius  of  828  feet  for .  architectural  effect.  The  volume  of  water  stored 
by  this  great  dam,  the  highest  in  existence,  is  comparatively  insignificant, 


25C)         liESERVOIRS  FOR  TRIUOATION,  WATER-POWER,  ETC. 

Lei  no-  but  J  297  iicrc-feet  (422,625,000  gallons).  M  .  Oracir,  Chief  Engineer 
of  Iho  Dcparinient  of  the  Loire,  and  M.  Delocre  designed  the  dam,  and  M. 
I^lonlgollier  was  engineer  in  charge  of  construction. 

The  Ternay  Dam. — Located  on  the  river  Ternay,  in  the  x)rovince  of 
Ardeche,  southern  France,  this  dam  was  erected  in  18G5  to  18G8,  for  con- 
trolling floods  and  supplying  the  neighboring  town  of  Annonay.  It  is  con- 
structed of  granite  rubble  masonry,  and  is  founded  on  bed-rock  of  granite., 
The  proportion  of  mortar  in  the  work  was  40%.  In  plan  it  is  curved  with, 
a  radius  of  1312  feet,  while  the  profile  is  a  gravity  type,  resembling  that, 
of  the  Furens  dam.  The  extreme  height  is  119  feet,  and  bottom  thickness 
89.2  feet.  The  up-stream  face  is  vertical  for  58.5  feet,  and  battered  below 
that  point.  The  lower  face  is  chiefly  formed  in  a  vertical  curve  of  147.6. 
feet  radius,  reaching  from  the  water-level  to  within  30.5  feet  of  the 
bottom,  the  slope  to  the  base'being  tangent  to  the  curve.  The  center  of 
the  circular  curve  is  7.5  feet  above  the  crown  of  the  dam. 

The  dam  was  designed  and  built  by  M.  Bouvier,  Engineer  des  Fonts  et 
Chaussees,  under  the  general  direction  of  J.  B.  Krantz,  Chief  Engineer. 
The  profile  of  the  dam,  however,  is  considerably  lighter  than  the  type 
recommended  by  M.  Krantz  in  his  "  Study  on  Reservoir  Walls,''  which, 
form  resulted  from  his  adherence  to  a  limiting  pressure  of  6  kilograms, 
per  square  centimeter  (85  lbs.  per  square  inch)  upon  any  portion  of  the 
masonry,  whereas  the  maximum  pressures  in  the  Ternay  dam  are  esti- 
mated to  be  9  kilos  per  square  centimeter.  M.  Krantz  comments,  how- 
ever, on  the  Ternay  dam  as  follows:  "  The  reservoir  wall  of  Ternay,  which 
was 'remarkably  planned  and  built  by  M.  Bouvier,  has,  in  my  opinion, 
scarcely  a  defect." 

The  capacity  of  the  reservoir  back  of  the  dam  is  686,766,000  gallons 
(2107  acre-feet).   The  total  cost  of  the  dam  was  $204,372. 

The  Vingeanne  Dam,  France.— This  structure  resembles  the  Ternay  in 
height  and  general  form,  being  113.8  feet  high,  18.1  feet  thick  at  base, 
11.5  feet  on  top.  It  is  located  near  the  town  of  Baissey,  and  was  built  in 
1885. 

The  Ban  Dam,  France.— Next  to  the  Furens  dam  in  height  the  reservoir 
wall  constructed  in  1867  to  1870,  near  the  city  of  St.  Chamond,  was  built 
upon  the  same  general  principles,  except  that  a  greater  maximum  pressure 
was  permitted  upon  the  masonry,  the  computed  extreme  being  8.18  tons 
per  square  foot.  Its  extreme  height  is  157  feet,  length  512  feet,  base  thick- 
ness 127  feet,  top  width  16.4  feet.  The  wall  is  battered  or  curved  on  botk 
sides,  there  being  no  vertical  faces.  In  plan  it  is  curved  convex  up-stream. 
It  is'  composed  of  rubble  masonry  founded  on  rock.  It  is  used  for  the 
supply  of  the  city  of  St.  Chamond,  and  its  cost  was  $190,000. 

The  Verdon  Dam,  France.— This  structure  is  not  of  great  height,  being 
but  59  feet,  but  its  construction  presented  great  difficulties,  owing  to  the. 


MASONRY  DAMS, 


257 


volume  of  water  carried  by  the  Verdon  River^  and  the  narrow  canyon  in 
which  it  was  placed.  The  low-water  flow  is  350  second-feet,  while  in  floods 
the  discharge  reaches  over  4200  second-feet.  The  dam  had  to  be  founded 
on  rock,  after  excavating  20  feet  through  gravel  and  bowlders;  and  as  the 
canyon  is  but  130  feet  wide  at  the  top  of  the  dam  and  considerably  less 
at  the  water-level,  there  was  little  room  to  do  the  work  and  take  off  the 
constant  flow. 

The  dam  is  used  for  diverting  water  to  a  canal,  supplying  the  city  of 
Aix  and  other  places  in  the  vicinity.  The  clam,  proper  is  curved  up-stream 
with  a  radius  of  108.8  feet,  resting  on  a  rectangular  base  of  concrete.  The 
masonry  consists  of  rubble  with  cut-stone  facings.  The  general  dimen- 
sions are: 


Length  on  top   131.3  feet. 

Thickness  of  base   32.5  " 

Thickness  of  crest   14.2  " 

Height  above  river-bed   40.2  " 

Height  above  foundations   59.0  " 


The  concrete  foundation  has  a  thickness  of  48  feet.  This  is  protected 
from  the  falling  water  by  an  embankment  of  large  blocks  of  loose  stone. 
The  maximum  depth  of  overflow  was  estimated  at  16.4  feet. 

The  Pas  Du  Riot  Dam,  France.— Subsequent  to  the  construction  of  the 
Furens  dam,  a  second  storage-reservoir  for  the  further  supply  of  the  city 
of  St.  Etienne  was  built  in  1872  to  1878  to  the  height  of  113.2  feet,  curved 
in  plan,  and  similar  in  profile  to  its  greater  neighbor.  The  reservoir  formed 
by  it  has  a  capacity  of  343,380,000  gallons  (1054  acre-feet).  The  cost  of  the 
dam  was  $256,000. 

The  Cotatay  Dam,  France.— In  1885  a  dam  was  built  on  the  Cotatay 
brook  near  the  city  of  St.  Etienne  to  supply  the  city  of  Chambon-Fen- 
gerolles.  This  also  is  of  the  Furens  type,  curved  in  plan,  and  of  the  same 
height  as  the  Pas  Du  Riot  dam— 113.2  feet. 

The  Pont  Dam,  France.— This  structure,  of  granite  rubble,  founded  on 
rock,  has  a  maximum  length  of  495  feet  and  an  extreme  height  of  85  feet. 
It  is  curved  in  plan,  with  a  radius  of  1312.4  feet.  The  base  thickness  is 
62  feet,  and  crest  16.4  feet.  The  water-face  batters  4.2  feet  in  its  total 
height. 

On  the  lower  face,  from  the  top  down  for  62.3  feet,  is  a  vertical  curve, 
whose  radius  is  98.4  feet.  The  remaining  height  has  a  batter  tangent  to 
this  curve.  Nearly  20  feet  of  the  base  of  the  dam  is  below  the  river-bed. 
Seven  counterforts  or  buttresses,  16  feet  long,  3  feet  thick,  help  sustain 
the  dam.  The  dam  was  built  in  1883  on  the  Armangon  River,  2J  miles  . 
from  the  city  of  Semur. 


258        UESEllVOIllS  FOB  IlilUGATION,  WATER-POWER,  ETC, 

The  Chartrain  Dam,  France.-Thc  profile  of  this  modern  structure, 
built  in  1888-1)2,  is  one  oi*  the  most  graceful  and  scientific  in  design  of  all 
of  the  French  dams  of  recent  construction.  It  has  a  maximum  height  above 
lowest  foundations  of  about  180  feet,  and  a  base  width  on  top  of  founda- 
tions of  135  feet,  the  foundations  extending  above  and  below  the  toes  ot  the 
wall  to  a  total  width  of  15G  feet. 

The  dam  is  located  on  the  river  Tache,  and  was  built  to  store  water 
for  the  supply  of  the  city  of  Roanne.  The  reservoir,  however,  is  quite 
small  for  so  high  and  costly  a  dam,  covering  but  54.36  acres  m  area  and 
impounding  3647  acre-feet  to  a  mean  depth  of  67  feet,  or  41%  of  the 

maximum  depth.  p    ,    .  ^ 

The  cost  of  the  dam  was  $420,000,  or  $115.10  per  acre-foot  of  storage 

capac^ty^^^^^^  Dam,  France.— The  failure  of  this  structure  April  27,  1895, 
with  the  loss  of  one  hundred  and  fifty  lives  and  the  destruction  of  much 
property,  has  particularly  emphasized  the  value  of  several  features  of 
masonry  dams  which  may  be  regarded  as  essential  in  the  design  of  all 
such  works: 

1st  That  they  be  founded  on  impermeable  bed-rock,  and  the  possi- 
bility of  upward  pressure  from  water  passing  through  fissures  be  avoided. 

2d.  That  they  shall  have  a  profile  of  such  dimensions  as  to  permit  ot 
no  tension  in  the  masonry.  ^ 

3d    That  the  masonry  shall  be  practically  impervious  to  water 

4th  That  it  be  curved  in  plan  to  avoid  temperature  cracks  and  move- 
ments as  the  result  of  expansion  and  contraction  of  the  masonry 

The  Bousey  was  lacking  in  all  of  these  essential  features,  and  its  failnre 
was  not  surprising  in  the  light  of  all  the  facts  that  have  been  pubhshed 
resjarding  it. 

It  w^as  built  in  1878  to  1881,  near  Epinal,  France,  across  the  small 
stream  of  Aviere  to  form  a  storage-reservoir  of  1,875,000,000  gallons  for 
supplying  the  summit  level  of  the  Eastern  Canal,  which  here  crosses  the 
Yosges  Mountains  in  connecting  the  rivers  Moselle  and  Saone  this  canal 
being  a  connecting  link  in  interior  navigation  between  the  Mediterranean 
and  the  North  Sea.  The  reservoir  was  fed  by  an  aqueduct  from  the 
Moselle  River.  The  reservoir  covered  an  area  of  247  acres.  The  general 
dimensions  of  the  dam  are  as  follows: 

.^^   1700  feet. 

Length  on  top  

Height  above  river-bed  

Height  above  foundations  •   "  '^^ 

Width  on  top   ^ 

Width  36  feet  below  water-level   18 


MASONRY  DAIrlS. 


259 


The  wall  was  vertical  on  the  water-face  from  top  to  bottom. 

The  masonry  was  founded  on  red  sandstone,  which  in  places  was 
fissured  and  quite  permeable,  with  springs  which  gave  trouble  in  construct- 
ing the  foundations.  The  foundation  was  not  excavated  to  solid,  im- 
permeable rock  under  the  entire  dam,  but  an  attempt  was  made  to  remedy 
this  deficiency  by  building  what  was  called  a  ^'  guard-waiy^  6.5  feet  thick 
on  the  upper  side  of  the  dam,  extending  down  below  the  foundations 
through  the  imperfect  rock  for  the  purpose  of  cutting  o'fi"  leakage  under- 
neath. This  was  carried  up  to  the  river-bed  and  lapped  against  the  main, 
wall.  The  dam  was  completed  in  1880,  and  the  following  year  water  was 
admitted.  When  it  had  reached  about  one-third  the  height,  33  feet  below 
the  top,  enormous  leakage,  amounting  it  is  said  to  2  cubic  feet  per  second, 
appeared  on  the  lower  side  of  the  dam,  partly  due  to  two  vertical  fissures 
or  expansion-cracks  in  the  wall.  March  14:,  1884,  when  the  water  had  risen 
to  within  10.4  feet  of  the  top,  the  pressure  was  sufficient  to  bulge  the 
wall  forward  for  44-4  feet,  forming  a  curve  convex  down-stream,  the  ex- 
treme movement  being  from  1  to  3  feet  according  to  different  authorities. 
Four  additional  fissures  then  appeared,  and  the  leakage  increased  to  about 
8,000,000  gallons  per  day.  These  cracks  opened  in  winter  and  closed  in 
summer.  The  water  was  kept  behind  the  dam  and  the  following  year 
allowed  to  rise  to  within  2  feet  of  the  top,  after  which  it  was  drawn  off, 
when  it  was  discovered  that  for  97  feet  the  dam  had  been  shoved  forward, 
separating  from  the  guard-wall,  and  numerous  cracks  were  found  on  the 
inner  face.  Extensive  repairs  were  then  undertaken.  The  joint  between 
the  main  wall  and  the  guard-wall  was  covered  with  masonry  and  sur- 
rounded by  a  bank  of  puddle,  10  feet  thick,  while  a  heavy,  inclined  buttress- 
wall  was  built  at  the  lower  toe,  deep  into  the  bed-rock,  and  toothed  into 
the  masonry  of  the  dam  to  prevent  the  tendency  to  slide  on  its  base.  This, 
abutment  was  nearly  20  feet  in  height,  and  its  base  was  84.3  feet  below  the 
top  of  the  dam,  making  the  total  thickness  of  base  71.6  feet.  Notwith- 
standing all  this  work  the  dam  was  fatally  weak  at  a  point  near  the  river- 
bed level,  where  the  line  of  resistance  falls  considerably  outside  the  middle 
third,  and  the  final  break  occurred  at  a  point  about  33  feet  below  the  top, 
where  the  fracture  was  almost  horizontal  longitudinally,  and  594  feet  of 
the  central  part  of  the  dam  was  overturned.  The  break  was  level  trans- 
versely for  about  12  feet  and  then  dipped  toward  the  outer  face.  The 
repairs  finished  in  1889  were  presumed  to  have  made  the  dam  safe,  and 
the  break  did  not  occur  for  six  years  afterwards,  during  which  time  the 
action  of  temperature-changes  is  presumed  to  have  produced  the  weak- 
ness resulting  in  the  final  catastrophe.  An  interesting  account  of  the  fail- 
ure of  the  dam  was  published  in  Engineering  News,  May  16  and  23,  1895. 
The  lesson  taught  by  it  will  be  serviceable  to  engineers  the  world  over. 

The  Mouche  Dam,  France. — The  purpose  of  this  structure,  completed 


2G0         HEISEUVOIRB  FOn  llUUaATION,  WATKli-rOWER,  ETC. 


in  ISDO,  is  simikir  to  that  oi'  tlio  Bousey  dam— to  form  a  storage-reservoir 
tor  I'lTdiiii--  a  Jiavigahle  canal.  It  is  located  on  the  Mouche  lliver,  near  the 
\'illni;-e  ol;  St.  C'iero-ues,  and  forms  a  reservoir  of  211.8  acres,  liaving  a  mean 
deplli  ol'  21)  feet  and  impounding  7010  acre-leet.  The  general  dimensions 
are  as  follows: 

Length  on  top  134G  feet. 

Maxinmni  height,  lowest  foundation  to  parapet.  111.5 

Height,  base  to  water-lme   94.5 

Width  of. base   G6.7  " 

Width  of  top   11-6  " 

The  up-stream  face  has  a  batter  of  1  foot  in  50,  while  the  down-stream 
batter  is  nearly  1  to  1.  ' 

The  dam  is  straight  in  plan  and  carries  a  roadway  over  the  top,  nearly 
25  feet  wide,  supported  by  arches  resting  on  abutment-piers  that  give  the 
required  extra  width.  There  are  forty  of  these  arches,  each  with  a  span 
of  26.2  feet. 

The  masonry  was  found  experimentally  to  weigh  134.2  lbs.  per  cubic 
foot,  and  the  computations  of  the  profile  were  made  on  that  basis,  pre- 
serving the  lines  of  pressure,  reservoir  full  and  empty,  well  within  the 
center  third. 

The  excavations  for  foundation  were  required  to  be  so  deep  to  reach 
bed-rock  that  56%  of  the  masonry  is  laid  below  the  surface,  the  maximum 
depth  of  excavation  being  about  40  feet.  The  water-face  of  the  dam  was 
given  three  coats  of  hot  pitch,  and  subsequently  whitewashed. 

The  Gileppe  Dam,  Belgium. — Xo  masonry  structure  of  modern  times 
has  so  great  a  section  as^this,  and  few  if  any  contain  such  an  enormous 
mass  of  masonry,  the  total  volume  of  which  is  325,000  cubic  yards,  all  of 
which  was  put  in  place  in  six  years,  from  1870  to  1875  inclusive.  The 
dam  is  most  imposing  in  appearance,  but  it  has  a  vast  excess  of  masonry 
beyond  safe  requirements,  the  effect  of  which  is  to  place  additional  stress 
upon  the  foundation  masonry  without  increasing  the  stability.  The  prin- 
cipal dimensions  are  as  follows: 

Maximum  height   154  feet. 

Length  on  top   '^'^1 

Breadth  on  top .,   49 

Breadth  at  base   216.5 


The  dam  is  curved  up-stream  on  a  radius  of  1640  feet.  It  was  designed 
by  M.  Bidaut,  Chief  Engineer,  who  occupied  nine  years  in  the  preliminary 


MA80WBY  BAMS. 


261 


studies  before  plans  were  submitted  to  the  Belgian  Government,  by  whom 
it  was  erected  to  regulate  the  flow  of  the  Gilepj^e  Eiver  and  provide  a  pure- 
water  supply  for  the  cloth  manufactories  at  the  city  of  Verviers. 

The  reservoir  formed  by  the  dam  covers  an  area  of  198  acres  and  im- 
pounds 3,170,000,000  gallons,  or  9730  acre-feet.  The  mean  depth  is  ^9 
feet,  or  just  one-third  the  maximum  depth.  The  capacity  of  the  reservoir 
is  about  one-half  the  average  annual  run-off  from  15.4  square  miles  of 
watershed. 

The  masonry  is  rough  rubble  throughout,  of  sandstone  quarried  on  the 
spot.  ThQ  dam  is  surmounted  by  a  cyclopean  statue  of  a  lion  sitting  on 
a  pedestal.    An  ample  carriageway  is  provided  across  the  dam. 

Considering  the  great  thickness  of  the  wall  and  the  care  taken  in  its 
•construction,  it  was  a  great  disappointment  to  find  on  filling  the  reservoir 
that  it  leaked  quite  considerably.  This  leakage  gradually  diminished  and  is 
-of  no  importance  as  affecting  the  stability  of  the  dam. 

The  entire  cost  of  the  dam  was  $874,000,  or  $89.83  per  acre-foot  of 
-storage  capacity. 

^  The  Remscheid  Dam,  Germany.— This  structure  is  one  of  the  best 
-existing  types  of  reservoir-walls  as  they  are  designed  and  built  by  modern 
German  engineers,  and  possesses  more  than  ordinary  interest.  It  is  82 
feet  high,  49.2  feet  thick  at  base,  13.1  feet  thick  at  crown,  and  is  curved 
in  plan,  with  a  radius  of  410  feet.  The  total  contents  of  the  dam  are  22,886 
■cubic  yards,  and  its  cost  is  given  at  $91,154,  an  average  of  $3.98  per  cubic 
yard.  The  reservoir  formed  by  it  has  a  capacity  of  35,310,500  cubic  feet, 
oi  811  acre-feet;  while  its  average  cost  was  $112.45  per  acre-foot  of  stor- 
age capacity. 

The  dam  is  built  across  the  Eschbach  valley,  and  is  designed  to  supply 
the  city  of  Eemscheid,  and  manufacturers  in  the  valley  below.    It  was 
begun  in  May,  1889,  and  water  turned  on  November,  1892.   It  is  composed 
•of  rubble  masonry,  the  stone,  a  hard  slate,  being  laid  in  trass  mortar.  Trass 
IS  a  rock  of  volcanic  origin,  from  Avhich  hydraulic  lime  is  made  resembling 
pozzuolana,  used  so  extensively  in  Italy.    The  mortar  consists  of  one  part 
lime,  one  and  one-half  parts  trass,  and  one  part  sand,  and  was  preferred 
by  the  engmeer  to  Portland  cement,  because  it  sets  more  slowly  and  tests 
showed  It  to  be  superior  in  point  of  elasticity.    The  dam  has  shown  no 
"Settlement,  no  cracks,  and  no  leaks.    The  courses  of  masonrv  were  laid 
so  as  to  be  as  nearly  perpendicular  as  possible  to  the  varying  direction  of 
the  resultant  pressures  at  all  points.    The  water-face  of  the  dam  was 
-plastered  with  cement  mortar,  over  which  two  coats  of  asphalt  were  placed 
-the  asphalt  extending  20  inches  over  the  bed-rock.     Then  a  bric^ 
i^all,  IJ  to  21  bricks  thick,  was  carried  up  outside,  tight  against  the 
asphalt.  ^  ^ 

The  dam  was  designed  and  built  by  Prof.  0.  Intze,  and  described  in  a 


262         RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 

paper  published  in  the  Journal  of  the  Society  of  German  Engineers,  from 
whicli  the  facts  above  given  are  gleaned. 

The  Einsiedel  Dam,  Germany.— This  dam  was  completed  in  1894,  and 
forms  a  reservoir  for  sui)plying  the  city  of  Chemnitz.  It  is  composed  of 
rubble  masonry,  the  total  volume  of  which  was  31,G00  cubic  yards.  Its. 
maximum  height  above  foundation  is  92  feet,  of  which  G5  feet  is  above 
the  natural  surface.  The  length  over  top  is  590  feet,  top  thickness  13  feet, 
base  65.5  feet.  It  is  curved  to  a  radius  of  1310  feet.  The  storage  capacity 
of  the  reservoir  is  95,000,000  gallons  (291  acre-feet). 

The  Gorzente  Dam,  Italy.— The  city  of  Genoa  derives  a  water-supply 
from  a  reservoir  formed  by  a  masonry  dam,  built  in  1882,  on  the  Gorzenta 
River.  The  reservoir  capacity  is  748,800,000  gallons  (2298  acre-feet), 
coverino'  64  acres.  The  dam  has  a  maximum  height  of  121.4  feet,  and  is. 
492  feet  long  on  top,  23  feet  thick  at  top,  99.6  feet  thick  at  base.  The 
masonry  is  a  rubble  composed  of  serpentine  rock  and  mortar  of  Casale  lime 
and  serpentine  sand. 

Ca^liari  Dam,  Italy.— This  structure  is  located  on  the  island  oi  bar- 
dinia  13  miles  from  the  city  of  Cagliari,  on  the  Corrungius  River.  It  was 
built  in  1866,  and  is  70.5  feet  high,  52.5  feet  thick  at  base,  16.4  feet  at 
top,  and  344.5  feet  long  on  top.  It  is  built  of  rubble  masonry  composed 
of  granite  and  a  hydraulic  lime  mortar,  mixed  with  clean,  well-washed, 
granitic  sand. 

The  Vyrnwy  Dam,  Wales.— Since  July  14,  1892,  the  city  of  Liverpool, 
England,  has  been  chiefly  supplied  by  water  from  a  large  storage-reservoir 
in  the  mountains  of  Wales,  77  miles  distant,  formed  by  a  monumental  dam 
of  masonry  erected  across  the  Vyrnwy  valley,  in  1882  to  1889.  The  dam 
has  a  top  length  of  1172  feet,  is  straight  in  plan,  and  has  a  maximum  height 
of  161  feet  from  foundation  to  parapet.  It  is  used  as  an  overflow-weir  over 
its  entire  length,  and  its  profile  was  designed  to  offer  additional  resistance 
over  that  presented  by  water-pressure  alone.  An  elevated  roadway  is, 
carried  across  the  dam  on  piers  and  arches,  above  the  level  of  flood-water, 
which  adds  greatly  to  the  architectural  effect  and  ornamentation  ot  the 
imposing  mass  of  masonry.  The  great  wall  is  composed  of  cut  stone.  The 
base  width  of  the  dam  is  117.75  feet.  The  back-water  level  below  the 
dam  is  45  feet  above  its  base. 

The  total  volume  of  masonry  in  the  dam  is  260,000  cubic  yards,  which 
was  laid  with  such  extraordinary  care  that  its  average  cost  was  nearly  $10 
per  cubic  yard,  in  a  country  where  materials  and  labor  are  of  the  cheapest 

The  base  of  the  dam  is  founded  on  a  hard  slate  rock,  and  one  end  of 
the  masonry  is  built  into  the  solid  wall  of  bed-rock  on  the  side  of  the 
valley  At 'the  other  end,  however,  the  rock  was  so  deeply  overlaid  with 
a  deposit  of  bowlder  clay  that  the  masonry  was  connected  with  this  material 
by  a  puddle-wall  of  clay  recessed  into  the  masonry. 


MASONRY  DAMS. 


263 


The  general  dimensions  of  the  dam  are  as  follows: 


Total  length  on  top   1172  feet. 

Maximum  height  on  top  of  roadway  parapet   161  " 

Height,  river-bed  to  parapet   101  " 

Height,  river-bed  to  overflow-level   81  " 

Greatest  width  of  base   120 

Batter  of  water-face   1  to  7.27  " 


The  cost  of  the  dam  is  given  as  follows: 


Borings  and  preliminary  work   $34,600 

Excavating  220,820  cu.  yds.  and  backfilling  79,501  cu.  yds   287,600 

Puddle-wall,  including  excavation.   16,800 

Masonry  and  brickwork   2,532,000 

Regulating  and  gauging  plant   46,000 

Basin  and  other  work  below  dam   40,000 


Total  for  dam  proper  $2,957,000 

In  addition  to  this  the  removal  of  a  village  in  the  basin,  the  building 
of  roads  around  the  lake,  culverts,  fencing,  planting,  dressing  slopes,  and 
erection  of  superintendent's  house  cost  $377,000,  or  a  total  of  $3,334,000. 

The  reservoir  formed  by  the  dam  covers  a  surface  area  of  1121  acres, 
and  impounds  12,131,000,000  Imperial  gallons,  or  44,690  acre-feet.  This 
gives  a  mean  depth  of  39.87  feet,  or  47.5%  of  the  maximum.  The  water- 
shed area  is  29  square  miles,  upon  which  the  minimum  recorded  rainfall 
is  49.63  inches,  and  the  maximum  118.51  inches. 

The  average  cost  of  the  dam  per  acre-foot  of  storage  capacity  formed 
by  it  was  $74.61. 

The  dam  was  planned  and  constructed  by  Geo.  F.  Deacon,  Chief 
Engineer,  Liverpool  Water-works.  Messrs.  Thos.  Hawkesley  and  J.  F. 
Bateman  were  consulting  engineers. 

Tests  made  by  Kirkaldy  of  large  blocks  of  the  concrete  and  masonry 
taken  from  the  dam  showed  a  compressive  strength  of  300  tons  per  square 
foot,  while  the  maximum  strains  to  be  borne  by  it  are  but  9  tons  per  square 
foot,  an  excess  of  strength  which  has  been  considerably  criticised. 

The  Habra  Dam,  Algiers.— The  French  Government  has  built,  or  en- 
couraged the  construction  by  private  parties  of,  a  number  of  notable  stor- 
age-reservoirs for  irrigation  in  Algiers,  of  which  the  largest  was  that 
formed  on  the  Habra  Eiver,  by  a  masonry  dam,  whose  disastrous  failure 
has  made  it  well  known  among  the  engineering  profession,  and  added  to 
the  many  lessons  which  such  failures  carry  with  them.    The  dam  was 


264         liESEliVOIRS  FOli  IRlilQATION,  WATEll-FOWER,  ETC. 


begun  in  November,  1865,  completed  in  May,  1873,  and  after  eight  years 
oi'  service  was  ruptured  in  December,  1881,  causing  the  loss  of  209  lives 
and  the  destruction  of  several  villages. 

The  main  dam  was  straight  in  plan  and  1066  feet  long  on  top,  flanked 
by  an  overflow  wall,  410  feet  long,  making  an  angle  of  35°  with  the  direc- 
tion of  the  dam,  the  top  of  which  was  5.2  feet  below  the  crest  of  the  dam 
proper. 

The  maximum  height  of  the  dam  was  117  feet  from  foundation  to  the 
water-line,  above  which  a  parapet  extended  8  feet  higher.  The  dam  was 
14  feet  thick  at  top,  88.4  at  base,  battered  on  both  sides  and  of  ample 
dimensions  to  withstand  the  water-pressure,  provided  the  masonry  had 
been  properly  constructed  and  of  first-class  material.  When  completed  and 
first  filled  the  dam  leaked  like  a  gigantic  filter,  but  the  leakage  practically 
ceased  in  course  of  time. 

The  reservoir  formed  by  the  dam  had  a  capacity  of  thirty  million  cubic 
meters,  or  24,330  acre-feet.  The  watershed  of  the  Habra  Eiver  is  very- 
extensive,  covering  3859  square  miles  above  the  dam,  from  which  the 
annual  discharge,  however,  was  only  about  3^  times  the  capacity  of  the 
reservoir,  owing  to  the  slight  rainfall  of  that  region.  The  summer  flow 
was  about  18  second-feet,  and  the  normal  winter  flow  was  about  100  second- 
feet,  while  extreme  floods  reached  25,000  second-feet  in  volume.  The 
flood  which  caused  the  rupture  of  the  dam  came  from  a  rainfall  of  6J 
inches  in  one  short  storm,  during  which  the  run-off  in  one  night  was 
computed  at  3,500,000,000  cubic  feet,  or  more  than  three  times  the  reser- 
voir capacity.  This  resulted  in  a  general  overflow  of  the  crest  of  the  wall, 
as  the  spillway  was  of  insufficient  capacity,  and  produced  such  excessive 
pressure  upon  the  outer  face  of  the  masonry  as  to  exceed  its  normal 
strength.   Over  300  feet  of  the  wall  was  torn  out  to  the  very  foundation. 

In  a  paper  on  the  subject  written  the  following  ;year  by  the  eminent 
Italian  engineer,  G.  Crugnola,  he  attributes  the  failure  to  inferiority  in  the 
quality  of  the  masonry.  The  sand  was  not  of  good  quality,  and  in  the  cen- 
ter of  the  dam  a  red  earth,  containing  22  to  24  per  cent  of  clay,  was  used 
instead  of  sand.  Furthermore,  the  mortar  was  made  of  hydraulic  lime 
burned  from  calcareous  rock  found  on  the  banks  of  the  river,  which,  though 
hydraulic,  was  not  very  good.  The  inference  drawn  by  M.  Crugnola  is  that 
the  hydraulic  lime  contained  a  quantity  of  quicklime,  which  expanded  in 
time,  causing  porosity  if  not  actual  cavities  in  the  interior  of  the  masonry. 
The  stone,  as  well  as  the  mortar,  was  extremely  porous,  consisting  chiefly 
of  calcareous  Tertiary  grit,  which  was  of  variable  hardness,  some  having  a 
decided  schistose  structure. 

One  must  conclude  from  all  the  facts  that  had  the  spillway  been  suf- 
ficient in  capacity  to  avoid  the  submersion  of  the  dam,  and  had  the  face 


MASONBT  DAMS. 


265 


of  the  wall  been  made  absolutely  water-tight  by  such  precautionary  meas- 
ures as  were  employed  on  the  Eemscheid  dam,  the  failure  would  not  have 
occurred.  The  curvature  of  a  wall  of  the  great  length  of  the  Habra  would 
doubtless  have  avoided  temperature  cracks,  which,  as  has  been  pointed 
out  by  Prof.  Forchheimer  (page  122),  may  have  been  a  leading  source  of 
weakness.  The  failure  occurred  during  the  coldest  weather,  when  such 
cracks  appear  in  masonry  walls. 

The  Hamiz  Dam,  Algiers. — N'ext  in  importance  to  the  Habra  dam,  and 
somewhat  higher,  is  the  Hamiz  dam,  erected  in  1885  on  the  Hamiz  Kiver. 
This  wall  is  also  straight  in  plan,  but  only  532  feet  in  length  on  top,  131 
feet  long  at  base.  The  extreme  height  above  foundation  is  134.5  feet,  and 
above  river-bed  91.2  feet,  and  at  top  16.4  feet.  Both  faces  are  curved  in 
outline. 

The  dam  impounds  10,500  acre-feet  of  water,  gathered  from  a  shed  of 
54  square  miles. 

The  Gran  Cheurfas  Dam,  Algiers. — This  structure  is  quite  similar  in 
dimensions  to  the  Hamiz  dam,  and  was  built  in  1882-84,  on  the  Mekerra 
Eiver,  9  miles  from  St.  Dionigi.  Its  foundation  extends  32.8  feet  below  the 
river-bed,  and  has  a  thickness  of  134.5  feet  at  base  and  78.7  feet  at  top. 
On  this  foundation  the  dam  proper  rests,  with  an  offset  of  3^  feet  on  each 
side,  making  its  thickness  at  bottom  72  feet,  while  at  top  the  wall  is  13  feet 
thick.  Both  faces  are  curved  in  parabolic  form,  presenting  a  graceful 
profile.  The  maximum  pressures  on  the  masonry  are  6.1  tons  per  square 
foot. 

The  dam  failed  in  part  when  first  filled,  and  a  breach  of  130  feet  was 
made  in  the  wall,  but  it  was  immediately  repaired.  The  failure  occurred  in 
winter.   The  dam  is  straight  in  plan. 

The  reservoir  capacity  behind  the  dam  is  about  13,000  acre-feet. 

The  Tlelat  Dam,  Algiers. — This  masonry  wall  is  69  feet  high,  325  feet 
long,  40  feet  thick  at  bottom,  13  feet  thick  at  top,  and  impounds  445  acre- 
feet,  derived  from  a  water-shed  of  51  square  miles.  The  dam  was  erected 
in  1869  on  the  Tlelat  Eiver  to  supply  the  town  of  Sante  Barbe,  7^  miles 
below,  and  also  for  irrigation.  The  wall  is  vertical  on  the  water-face,  while 
the  lower  side  has  a  vertical  curve,  the  center  of  radius  being  11.8  feet 
above  the  top  of  the  dam. 

The  Djidionia  Dam,  Algiers,  is  83.7  feet  in  extreme  height,  of  which 
28  feet  is  foundation  below  the  river-bed  level.  The  face  is  vertical,  and 
the  dam  is  straight  in  plan.  The  foundation  is  broader  on  top  than  the 
bottom  of  the  dam,  and  will  permit  of  an  increased  height  in  the  structure 
by  adding  to  the  lower  side  from  the  foundation  up.  This  has  been  de- 
cided upon,  and  26  feet  additional  in  height  will  be  built.  The  reservoir 
will  then  have  a  capacity  of  about  4000  acre-feet.    The  dam  was  built  in 


2GG        EESKRVOinS  FOE  IRRIGATION,  WATER-POWER,  ETC. 


1873-75,  on  the  Djidionia  River,  to  supply  the  towns  of  St.  Aime  and 
Amadema  with  water.  The  masonry  of  this  dam  is  slightly  in  tension  on 
the  water-face  when  the  reservoir  is  filled,  amounting  to  abont  15  lbs.  per 
square  inch,  but  no  injurious  elt'ect  upon  the  masonry  is  apparent  from 
this  small  tensile  strain. 

The  Tansa  Dam,  India.* — This  great  dam,  forming  a  reservoir  for  the 
supply  of  Bombay,  was  begun  in  1886,  and  completed  in  April,  1891.  The 
work  was  done  by  contract  and  cost  $988,000.  It  is  straight  in  plan,  the 
alignment  consisting  of  two  tangents,  and  it  has  a  total  length  of  8800 
feet,  the  maximum  height  being  118  feet.  For  a  length  of  1650  feet  the 
dam  is  depressed  3  feet,  to  serve  as  a  waste-weir.  The  thickness  of  the 
masonry  at  the  base  is  96.5  feet,  and  the  entire  section  is  made  of  sufficient 
dimensions  for  an  ultimate  height  of  135  feet,  to  which  it  may  be  raised 
in  future,  when  its  length  will  be  9350  feet  on  top. 

The  dam  was  built  with  native  labor,  and  consists  of  uncoursed  rubble 
masonry  throughout,  all  the  stones  being  small  enough  to  be  carried,  by 
two  men.  The  stone  is  a  hard  trap-rock,  quarried  on  the  spot.  The 
cement  was  burned  at  the  site  of  the  dam  from  nodules  of  hydraulic  lime- 
stone, called  kunkur,  which  are  found  throughout  India,  and  occur  in  clay 
deposits,  although  in  this  case  it  had  to  be  brought  long  distances  by  rail 
and  carts.  Most  Indian  masonry  is  made  with  kunkur  hydraulic  lime. 
The  nodules  require  to  be  exposed  to  the  sun,  dried  and  washed  before 
being  burned.  They  are  usually  of  one  or  two  pounds  weight,  although 
sometimes  found  in  blocks  of  100  lbs.  or  more. 

From  9000  to  12,000  men  were  employed  on  this  dam  during  the  work- 
ing season  of  each  year,  from  May  to  October,  but  during  the  monsoons  all 
work  was  suspended. 

The  volume  of  masonry  in  the  work  is  408,520  cubic  yards.  It  is 
reported  to  be  entirely  water-tight.  The  excavation  was  carried  to  a 
considerable  depth  in  places,  and  necessitated  the  removal  of  251,127  cubic 
yards  for  the  foundations. 

The  reservoir  covers  an  area  of  5120  acres  and  impounds  62,670  acre- 
feet  above  the  level  of  the  outlets,  which  are  placed  25  feet  below  the  crest 
of  the  spillway,  or  89  feet  above  the  river-bed.  The  loss  by  evaporation 
reduces  the  available  supply  to  15,870  acre-feet,  although  of  course  many 
times  this  quantity  could  be  drawn  from  the  lake  if  the  outlets  were  near 
the  bottom.  The  watershed  area  is  52.5  square  miles,  on  which  the  precipi- 
tation is  from  150  to  200  inches  annually,  and  the  estimated  annual  run- 
off is  267,000  acre-feet. 

*  See  Proceedings  Institution  of  Civil  Engineers,  vol.  cxv.  Paper  by  W.  J.  C. 
Gierke,  M.I.C.E.,  on  "The  Tansa  Works  for  the  Water-supply  of  Bombay";  also. 
"  Irrigation  in  India,"  by  Herbert  M.  Wilson,  13th  Annual  Report  U.  S.  Geological 
Survey. 


MASONRY  DAMS. 


267 


The  dam  was  planned  and  built  by  W.  J.  C.  Gierke,  Chief  Engineer. 

The  Poona  or  Lake  Fife  Dam,  India.* — This  was  one  of  the  first 
masonry  dams  built  in  India  by  the  British  Government  for  irrigation 
storage;,  and  was  begun  in  1868.  It  is  made  of  uncoursed  rubble  masonry, 
founded  on  solid  bed-rock,  and  is  straight  in  plan,  having  a  top  length  of 
5136  feet  (nearly  a  mile),  of  which  1453  feet  is  utilized  as  a  wasteway. 
Its  maximum  height  above  foundation  is  108  feet,  and  above  the  river-level 
98  feet. 

The  design  of  the  dam  is  extremely  amateurish.  The  up-stream  batter 
is  1  in  20,  and  the  down-stream  slope  1  in  2,  unchanged  from  top  to  bottom, 
the  top  width  being  14  feet,  and  the  base  61  feet.  The  alignment  of  the 
dam  is  in  several  tangents  with  different  top  width  for  each,  according  to 
its  height,  the  points  of  junction  being  backed  up  by  heavy  buttresses  of 
masonry.  When  completed  the  dam  showed  signs  of  weakness  and  was 
strengthened  by  an  embankment  of  earth,  60  feet  wide  on  top,  30  feet 
high,  piled  up  against  the  lower  side. 

The  water  is  drawn  from  the  reservoir  59  feet, above  the  river-bed, 
and  there  is  therefore  available  but  29  feet  of  the  total  depth  of  the  reser- 
voir. The  amount  available  above  this  level  is  75,500  acre-feet.  The  lake 
is  14  miles  long  and  covers  an  area  of  3681  acres. 

The  dam  is  located  10  miles  west  of  the  town  of  Poona,  on  the  Mutha 
Eiver.  Its  cost  was  $630,000,  and  it  contains  360,000  cubic  yards  of 
masonry. 

The  canal  on  the  right  bank  is  23  feet  wide,  8  feet  deep,  and  99.5 
miles  long,  drawing  412  second-feet  from  the  reservoir  and  distributing 
it  over  147,000  acres  of  land  to  be  irrigated.  At  the  town  of  Poona  a 
drop  of  2.8  feet  is  utilized  for  power  by  an  undershot  wheel,  to  pump 
water  to  supply  the  town.  The  left-bank  canal  is  14.5  miles  long  and 
carries  38  second-feet.  The  sluices  from  the  reservoir  are  each  2  feet 
square,  closed  by  iron  gates  operated  by  capstan  and  screw  from  the  top 
of  the  dam.  Ten  of  these  supply  the  larger  canal,  and  three  discharge 
into  the  smaller  one.  Eight  additional  circular  sluices,  30  inches  in 
diameter,  supply  water  to  natives  for  mill-power  and  discharge  into  the 
larger  canal. 

The  Bhatgur  Dam,  India.f— There  are  no  masonry  structures  in  the 
United  States  or  Europe  which  surpass  in  size  those  of  India  which  have 
l3een  constructed  for  irrigation  purposes  by  the  British  Government,  in 
the  attempt  to  render  the  great  population  of  that  country  self-supporting 


*  "Irrigation  in  India,"  by  H.  M.  Wilson,  in  12th  Annual  Report  IT.  S.  Geological 
Survey, 
f  lUd. 


208 


llESEllVOIliS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


and  check  the  friglitlul  famines  by  which  it  has  been  periodically  devas- 
tated. 

The  Bhatgiir  dam,  constructed  on  the  Yelwand  Eiver,  about  40  miles 
south  of  Toona,  is  one  of  the  most  notable  of  these  great  structures.  Its 
length  on  top  is  40G7  feet,  its  extreme  height  above  foundations  is  127 
feet,  and  it  forms  a  reservoir  15  miles  in  length,  having  a  capacity  of 
120,500  acre-feet.  The  extreme  bottom  width  of  the  dam  is  74  feet,  and 
the  crest  is  12  feet  wide,  forming  a  roadway.  The  alignment  of  the  dam 
curves  in  an  irTegular  way  across  the  valley,  so  as  to  follow  the  outcrop  of 
bed-rock  on  which  it  is  founded.  The  section  of  the  dam  was  designed 
after  a  formula  similar  to  that  deduced  by  M.  Bouvier,  and  all  the  calcula- 
tions were  worked  out  by  Mr.  A.  Hill,  M.I.C.E.,  who  was  afterwards 
assistant  on  the  construction  of  the  Tansa  dam.  The  curve  adopted  for 
the  lower  face  was  a  catenary,  but  the  wall  was  actually  built  in  a  series 
of  batters. 

The  three  primary  conditions  of  the  design  were: 

1st.  The  intensity  of  the  vertical  pressure  was  nowhere  to  exceed  120 
lbs.  per  square  inch  (8.04  tons  per  square  foot); 

2d.  The  resultant  pressures  were  to  fall  within  the  middle  third  of  the 
section;  and 

3d.  The  average  weight  of  the  masonry  was  assumed  at  100  lbs.  per 
cubic  foot.  The  use  of  concrete  was  only  permitted  where  the  pressure 
was  calculated  not  to  exceed  00  lbs.  per  square  inch,  which  gave  a  factor 
of  safety  of  between  0  and  7. 

The  dam  was  designed  and  built  by  J.  E.  Whiting,  M.I.C.E. 

Waste-weirs  at  each  end  of  the  dam  have  a  total  length  of  810  feet, 
and  can  carry  8  feet  depth  of  water.  The  roadway  is  carried  over  these 
weirs  on  a  series  of  10-foot  arches.  Additional  flood-discharge  is  given 
by  twenty  under-sluices,  4x8  feet  in  size  (of  which  fifteen  are  located  00 
feet  below  the  crest),  having  a  total  capacity  of  20,000  second-feet.  These 
sluices  are  lined  with  cut  stone,  and  closed  by  iron  gates,  operated  from 
the  top  of  the  dam.  The  overflow  wasteway  is  closed  by  a  novel  series  of 
automatic  gates  that  open  in  flood  and  rise  up  into  position  as  the  flood 
recedes,  permitting  the  full  storage  of  the  additional  8  feet  depth  to  be 
utilized.  The  gates  are  nicely  balanced  by  counterweights  that  occupy 
pockets  in  the  masonry.  As  the  water  rises  to  the  top  of  the  gate  it  fills 
these  pockets,  reducing  the  weight  of  the  counterpoises,  and  the  gate,  being 
then  heavier,  will  descend  below  the  crest  of  the  weir.  When  the  level  of 
the  flood  is  reduced  so  that  it  no  longer  enters  the  pockets,  the  latter  are 
emptied  by  small  holes  in  the  bottom,  and  the  counterpoises  overcome  the 
weight  of  the  gates,  lifting  them  into  place  again. 

The  reservoir  is  used  to  supply  the  Nira  Canal,  which  heads  19  miles 
below.   This  canal  is  129  miles  long,  23  feet  wide,  7.5  feet  deep,  and  carries 


MASONRY  DAMS. 


2G9 


470  second-feet,  supplying  300  square  miles  of  land.  The  water  is  diverted 
to  it  by  a  masonry  diverting-dam,  known  as  the  Vir  weir,  which  is  of  itself 
an  important  structure,  being  2340  feet  long,  43.5  feet  high,  constructed 
of  concrete  faced  with  rubble  masonry.  Its  top  width  is  9  feet.  Maximum 
floods  of  158,000  second-feet  pass  over  its  crest  to  a  depth  of  8  feet,  coming 
from  a  watershed  of  700  square  miles.  A  secondary  dam,  forming  a  water- 
cushion,  is  located  2800  feet  down-stream.  This  is  615  feet  long,  24  feet 
high,  built  of  masonry  founded  on  bed-rock,  and  carries  a  roadway  over 
its  crest.  During  maximum  floods  the  water  is  32  feet  deep  in  the  cushion, 
when  the  water  is  8  feet  deep  over  the  main  dam. 
The  works  were  finished  in  1890-91. 

The  Betwa  Dam,  India.* — This  masonry  structure  forms  a  diversion- 
weir  for  turning  the  water  of  the  Betwa  River  into  a  large  irrigation-canal, 
and  also  serves  for  storage  to  the  extent  of  36,800  acre-feet,  which  is  the 
capacity  of  the  reservoir  above  the  canal  flow,  although  not  all  available. 

The  total  length  of  the  dam  is  3296  feet,  and  its  maximum  height  is 
50  feet.  It  has  an  extremely  heavy  profile,  being  15  feet  thick  at  top  and 
61.5  feet  at  base.  At  its  highest  part  the  down-stream  face  is  vertical,  and 
a  large  block  of  masonry  15  feet  thick  reinforces  the  dam  at  its  lower  toe. 
It  consists  of  rubble  masonry  laid  in  native  hydraulic  lime,  with  a  coping 
of  ashlar,  18  inches  thick,  laid  in  Portland-cement  mortar. 

In  plan  the  dam  is  divided  into  three  sections,  of  different  lengths,  by 
two  islands,  and  is  irregular  in  alignment. 

The  canal  floor  is  placed  21.5  feet  below  the  crest  of  the  dam.  A 
masonry  subsidiary  weir,  12  feet  wide  on  top,  18  feet  high,  to  form  a  water- 
cushion  for  the  overflow  of  the  dam,  was  built  1400  feet  below,  across  the 
main  channel,  and  a  second  subsidiary  weir,  200  feet  below  the  main  weir, 
was  made,  to  check  the  right-bank  channel  at  the  same  level.  The  main 
dam  and  subsidiary  weirs  cost  $160,000,  not  including  the  regulating  and 
flushing  sluices,  which  cost  $10,000.  The  main  canal  is  19  miles  long,  and 
with  its  branches  supplies  150,000  acres. 

The  Periyar  Dam,  India. — None  of  the  modern  structures  for  irrigation 
storage  in  India  have  presented  greater  difficulties  than  the  great  dam 
erected  across  the  Periyar  River,  which  was  begun  in  1888  and  completed 
in  1897.  The  project,  of  which  the  dam  was  the  basis,  includes  the  con- 
struction of  a  wall  to  close  the  valley  of  the  Periyar  River  to  store  300,000 
acre-feet  of  water;  of  the  construction  of  a  tunnel  6650  feet  long,  through 
the  mountain-ran.sre  dividing  the  valley  of  the  Periyar  from  that  of  the 
Vigay  River,  for  the  purpose  of  drawing  ofp  the  water  of  the  reservoir, 
with  the  necessary  sluices  and  subsidiary  works  for  controlling  the  water 
on  its  way  down  a  tributary  of  the  Yigay;  and  finally  the  necessary  works 

*  See  "Irrigation  in  India,"  by  H.  M.  Wilson,  in  12tli  Annual  Report,  U.  S.  Geo- 
logical Survey. 


270         HESEliVOlllS  FOR  IRRWAIION,  WATER-ROWER,  EIG^ 

for  ilie  diversion,  regulation,  and  distribution  o£  the  water  for  the  irriga- 
tion oi'  14:0,000  acres  in  the  Vigay  valley,  ot  which  area  the  water-supply 
of  the  A^gay  was  only  suthcient  for  irrigating  20,000  acres. 

The  dam  is  155  feet  high  above  the  river-bed,  with  a  parapet  5  feet 
higher,  the  foundations  reaching  to  a  depth  of  173  feet  below  the  crest. 
It  is  12  feet  thick  at  top  and  11-1.7  feet  at  base,  and  is  constructed  through- 
out of  concrete  composed  of  25  parts  of  hydraulic  lime,  30  of  sand,  and  100 
of  broken  stone.  The  water-face  is  plast-ered  with  equal  parts  of  hydraulic 
lime  and  sand.  The  length  of  the  dam  on  top  is  1231  feet.  Its  cubic  con- 
tents are  about  185,000  cubic  yards  of  masonry. 

A  wasteway  has  been  excavated  on  each  side  of  the  dam,  one  of  which 
is  420  feet  long,  and  the  other  500  feet  long.  The  latter  is  partially  formed 
by  a  masonry  wall  403  feet  long,  filling  a  saddle-gap.  The  crests  of  these 
wasteways  are  16  feet  below  the  top  of  the  parapet.  The  rock  is  a  hard 
syenite.  The  maximum  floods  of  the  river  reach  120,000  second-feet  at 
times.  The  drainage-area  above  the  dam  is  300  square  miles,  on  which 
the  rainfall  is  from  69  to  200  inches,  averaging  125  inches  per  annum. 

The  river  is  one  that  is  subject  to  violent  and  sudden  floods,  in  an 
uninhabited  tract  of  country,  far  even  from  a  village,  some  85  miles  from 
the  nearest  railway,  where  there  were  no  roads  or  even  paths,  in  the 
midst  of  a  range  of  hills  covered  with  dense  forests  and  jungles  tenanted 
by  wild  beasts,  where  malaria  of  a  malignant  type  is  prevalent,  where  the 
commonest  necessaries  of  life  were  unobtainable,  and  where  the  incessant 
rain  for  half  the  year  prevented  the  importation  of  labor  and  rendered 
all  work  in  the  river-channel  impossible  for  six  months  out  of  every 
twelve.  During  the  first  two  years  of  construction  watchmen  with  drums 
and  blazing  fires  had  to  guard  every  camp  at  night  against  the  curiosity 
of  wild  elephants  that  constantly  visited  the  works,  uprooting  milestones, 
treading  down  embankments,  breaking  up  fresh  masonry,  playing  with 
cement-barrels,  chewing  bags  of  cement  and  blacksmith's  bellows,  kneeling 
on  iron  buckets,  and  doing  everything  that  mischief  could  suggest  and 
power  perform. 

The  limestone  for  making  the  hydraulic  lime  was  brought  a  distance 
of  16  miles,  surmounting  an  elevation  of  1300  feet  by  an  endless  wire 
rope,  3  miles  long,  to  which  the  stone  was  brought  by  wagon-road.  From 
the  lower  end  of  the  ropeway  the  stone  was  carried  on  a  short  tramway  to 
canal-hoats  plying  on  the  river  as  far  down  as  the  dam,  the  stream  having 
heen  made  navigable  for  this  purpose. 

The  sand  used  was  dredged  from  the  river-bed. 

This  brief  summary  of  the  unusual  conditions  under  which  the  dam 
was  built,  gleaned  from  a  paper  written  by  Mr.  A.  T.  Mackenzie, 
A.M.I.C.E.,  gives  a  general  idea  of  the  extraordinary  difficulties  which  had 
to  be  overcome  in  constructing  this  great  work,  which  is  certainly  one  of 


MASONRY  DAMS. 


271 


the  most  notable  of  the  many  monuments  to  English  engineering  in 
India. 

The  total  cost  of  all  the  works  connected  with  the  project  amounted 
to  about  $3,220,000.  The  estimated  net  revenues  were  $260,000  annu- 
ally. 

The  dam  was  designed  and  constructed  by  Col.  Pennycuick,  Chief 
Engineer.  It  is  so  designed  (by  M.  Bouvier's  formula)  that  the  greatest 
pressure  on  front  and  back  shall  not  exceed  9  tons  per  square  foot,  and 
the  lines  of  pressure  are  kept  within  the  middle  third.  Most  modern  dams 
of  any  magnitude  have  been  built  of  uncoursed  rubble  masonry.  Col. 
Pennycuick  justifies  the  use  of  concrete  in  the  Periyar  dam  in  the  follow- 
ing language,  as  quoted  by  Mr.  Wilson:  "  Concrete  is  nothing  more  than 
imcoursed  rubble  masonry  reduced  to  its  simplest  form,  and  as  regards 
resistance  to  crushing  or  to  percolation  the  value  of  the  two  materials  is 
identical,  unless  it  be  considered  as  a  point  in  favor  of  concrete  that  it 
must  be  solid,  while  rubble  may,  if  the  supervision  be  defective,  contain 
void  spaces  not  filled  with  mortar.  The  selection  depends  entirely  upon 
their  relative  cost,  the  quantities  of  materials  in  both  being  practically 
identical.^" 

In  this  opinion  of  the  value  of  concrete  he  is  less  conservative  than 
the  engineers  of  the  Tansa  dam,  who  limited  the  use  of  concrete  to  the 
upper  portion  of  the  dam,  where  the  limit  of  pressure  did  not  exceed  60 
lbs.  per  square  inch. 

While  the  full  reservoir  capacity  is  305,300  acre-feet,  the  level  of  the 
outlet-tunnel  is  such  that  but  156,400  acre-feet  can  be  utilized,  although 
this  may  be  supplied  several  times  annually. 

The  Beetaloo  Dam,  South  Australia. — Like  the  Periyar  dam  in  India 
and  the  San  Mateo  dam  in  California,  this  structure  is  composed  entirely 
of  concrete,  of  which  about  60,000  cubic  yards  were  used. 

The  dam  was  built  in  1888-90,  to  form  a  reservoir  of  2945  acre-feet 
capacity  for  irrigation  and  domestic  water-supply. 

The  dam  is  580  feet  long  on  top,  curved  in  plan,  with  a  radius  of 
1414  feet,  and  designed  after  Prof.  Pankine's  logarithmic  profile  type. 
The  maximum  height  is  110  feet,  the  base  width  being  the  same  as  the 
height.  The  thickness  at  top  is  14  feet.  The  spillway  is  200  feet  long, 
5  feet  deep.   The  cost  was  $573,300. 

Water  is  distributed  entirely  by  pipes  under  pressure,  some  255  miles 
of  pipe  from  2  to  18  inches  diameter  being  required. 

The  dam  was  designed  and  built  by  Mr.  J.  C.  B.  Moncrieff,  M.I.C.E., 
Chief  Engineer. 

The  Geelong  Dam,  Australia. — This  structure  is  also  constructed  wholly 
of  concrete,  made  of  broken  sandstone  and  Portland  cement,  in  the  pro- 
portion of  1  of  cement  to  7J  of  aggregates. 


272         UESEliVOlliS  FOR  UUUGATION,  WATER-POWeA;  ETC. 


The  dam  is  GO  feet  high,  39  feet  thiek  at  base,  and  2.5  feet  on  crest. 
It  is  curved  in  phin  on  a  radius  of  300  feet  from  the  water-face  at  crest. 
The  coping  is  formed  of  heavy  hluestone  of  large  size,  cut  and  set  in 
cement.  The  worlv  wa:fe  carried  up  evenly  in  courses  a  few  inches  thicl^:, 
and  thoroughly  rammed.  ^  The  surface  of  the  linished  concrete  was  wetted 
and  coated  with  cement  grout  before  adding  a  fresh  layer  to  it. 

The  dam  forms  a  reservoir  for  the  supply  of  the  city  of  Victoria.  Water 
is  drawn  from  it  by  two  24-inch  pipes  passing  through  the  masonry,  one 
of  which  is  used  for  scouring  purposes.  The  dam  leaked  slightly  at  the 
outset,  but  this  leakage  quickly  disappeared. 

The  Tytam  Dam,  China. — This  modern  English  structure  was  built 
to  store  water  for  the  supply  of  Hong  Kong.  It  is  about  95  feet  high,  and 
is  intended  to  go  20  feet  higher.  The  present  crest  width  is  21  feet,  base 
about  65  feet.  The  water-face  of  the  wall  is  almost  vertical,  the  outer  face 
being  stepped  in  10  feet  vertical  courses.  The  water-face  is  laid  up  in 
granite  ashlar,  the  remainder  being  concrete,  v/ith  stones  of  2  to  6  cubic 
feet  embedded.  About  40%  of  the  entire  wall  is  composed  of  stone,  and 
60%  of  concrete.  The  screenings  of  crushed  granite  were  used  as  sand, 
together  with  some  river  sand,  which  was  scarce,  and  used  without  wash- 
ing, as  it  was  believed  the  rock  dust  and  fine  particles  of  soil  would  con- 
duce to  water-tightness.  The  strength  of  the  mortar  was  less  of  a 
consideration  than  the  securing  of  a  water-tight  wall. 

The  Assuan  Dam,  Egypt. — A  dam  is  under  construction  at  the  present 
time  across  the  Upper  Nile,  in  Egypt,  by  English  capitalists  and  English 
engineers,  which  in  many  respects  is  equal  to  the  boldest  and  most  ex- 
tensive storage  works  constructed  in  India.  The  dam  is  intended  to  form 
a  reservoir  in  the  Mle  valley,  whose  storage  capacity  is  about  1,031,500 
acre-feet,  for  the  irrigation  of  a  tract  of  2500  square  miles  of  land,  located 
some  350  miles  down  the  valley  of  the  Nile  below  the  dam.  Water 
released  from  the  reservoir  travels  down  the  Nile  a  distance  of  330  miles 
to  a  point  called  Assiout,  where  a  diverting-dam  is  being  constructed  to 
raise  the  water  to  the  level  of  the  canal. 

The  Assuan  dam  is  to  be  about  6400  feet  long,  founded  on  granite 
rock  throughout,  and  having  a  maximum  height  of  90  feet  above  founda- 
tions. The  thickness  of  masonry  at  base  will  be  about  80.4  feet,  and  the 
top  width  23  feet,  the  crest  being  9.84  feet  above  the  estimated  level^  of 
high  water  in  the  reservoir,  and  carrying  a  roadway.  It  is  built  of  granite, 
uncoursed  rubble,  the  stone  being  quarried  from  adjoining  ledges  of  red 
syenite  The  wall  will  have  one  hundred  and  forty  culverts  or  under- 
sluices  passing  through  it,  each  23  feet  high  and  6.56  feet  wide,  and  forty 
upper  sluices,  having  one-half  the  area  of  the  lower  culverts.  These  are 
to  be  employed  for  the  passage  of  extraordinary  floods  and  the  scouring 
of  silt  from  the  reservoir.   All  of  the  upper  sluices  and  twenty  of  the  lower 


MASOJVMY  DAMS. 


273 


ones  will  be  lined  with  cast  iron,  and  the  remainder  with  cut-stone  ashlar. 
The  piers  between  sluices  are  16.4  feet  wide,  with  an  abutment-pier  at 
every  tenth  sluice,  39.37  feet  wide. 

The  maximum  floods  of  the  Nile  are  estimated  to  discharge  490,000 
second-feet,  and  a  mean  maximum  of  about  350,000  second-feet. 

The  sluices  will  all  be  opened  during  floods.  The  under-sluices  will 
be  regulated  by  Stoney's  self-balanced  gates.  A  navigation-canal  will  be 
taken  around  the  west  end  of  the  dam,  5250  feet  long,  having  four  locks, 
with  a  total  descent  of  68.9  feet.  This  canal  will  be  excavated  partly  in 
rock  and  partly  formed  by  an  embankment.  It  will  be  49.2  feet  wide  on 
bottom.  The  dam  and  locks  are  estimated  to  cost  $6,125,000,  and  are 
being  built  by  English  contractors,  who  agree  to  complete  the  work  by 
July  1,  1903. 

The  dam  was  designed  by  Mr.  W.  Willcocks,  M.I.C.E.,  in  the  service  of 
the  Egyptian  Government. 

The  Assiout  Dam,  Upper  Egypt.*— In  connection  with  the  utilization 
of  water  stored  in  the  great  Assuan  reservoir  a  diverting-weir  is  being 
erected  across  the  Nile,  below  the  head  of  the  Ibrahimia  Canal,  which  is 
estimated  to  cost  $2,245,000,  including  the  navigation-canal  and  locks. 

This  dam  is  also  of  masonry,  and  will  have  a  total  length  of  3930  feet, 
and  a  maximum  height  of  48  feet.  The  dam  will  have  one  hundred  and 
twenty  sluices,  each  16.4  feet  wide,  with  piers  6.56  feet  wide  between  them. 
The  navigation-lock  will  be  262  feet  long,  52.5  feet  wide,  capable  of 
passing  the  largest  steamers  that  ply  on  the  Nile.  It  is  located  about  200 
miles  above  Cairo.  The  head-works  of  the  Ibrahimia  Canal  will  cost 
$380,000. 

The  loss  of  water  from  evaporation  and  seepage  in  the  Assuan  reser- 
voir, and  in  traversing  the  distance  of  330  miles  to  Assiout,  is  estimated  at 
about  21.5%,  leaving  736,800  acre-feet  as  the  net  amount  available  for 
irrigation. 

*  See  Engineering  Record,  Dec.  30,  1899. 


CHAPTEE  IV. 


EARTHEN  DAMS. 

The  earliest  constructions  for  water-storage  of  which  there  is  historical 
record  have  been  earthen  dams  erected  to  impound  the  water  for  irrigation. 
India  and  Ceylon  afford  examples  of  the  industry  of  their  inhabitants  in 
the  creation  of  storage-reservoirs  in  the  earliest  ages  of  civilization,  which 
for  number  and  size  are  almost  inconceivable.  Excepting  the  exaggerated 
dimensions  of  Lake  Moeris  in  central  Egypt,  and  the  mysterious  basin  of 
"  Al  Aram/'  the  bursting  of  whose  embankment  devastated  the  Arabian 
city  of  Mareb,  no  similar  constructions  formed  by  any  race,  whether  ancient 
or  modern,  exceed  in  colossal  magnitude  the  stupendous  tanks  of  Ceylon. 
The  reservoir  of  Koh-rud  at  Ispahan,  Persia,  the  artificial  lake  of  Ajmeer, 
or  the  tank  of  Hyder  in  Mysore,  cannot  be  compared  in  extent  or  grandeur 
with  the  great  Ceylonese  tanks  of  Kalaweva  or  Padavil-colon.  The  first 
Ceylon  tank  of  which  there  is  historical  record  was  built  by  King  Pandu- 
waasa  in  the  year  504  B.C.  The  tank  of  Kalaweva  was  constructed  a.d.  459, 
and  was  not  less  than  40  miles  in  circumference.  The  dam  or  embank- 
ment of  earth  which  formed  it  was  more  than  12  miles  in  length,  and  the 
spillway  of  stone  is  described  by  the  historian  Tennent  as  "  one^  of  the 
most  stupendous  monuments  of  misapplied  human  labor  on  the  island.'' 
The  same  author  describes  the  tank  of  Padavil  as  follows: 

"  The  tank  itself  is  the  basin  of  a  broad  and  shallow  valley,  formed 
by  two  lines  of  low  hills,  which  gradually  sink  into  the  plain  as  they 
approach  the  sea.  The  extreme  breadth  of  the  enclosed  space  may  be  12 
or  14  miles,  narrowing  to  11  at  the  spot  where  the  retaining  bund  has 
been  constructed  across  the  valley.  ...  The  dam  is  a  prodigious  work,  11 
miles  in  length,  30  feet  broad  at  the  top,  and  about  200  feet  at  the  base, 
upwards  of  70  feet  high,  and  faced  throughout  its  whole  extent  by  layers 
of  squared  stone.  .  .  .  The  existing  sluice  is  remarkable  for  the  ingenuity 
and  excellence  of  its  workmanship.  It  is  built  of  hewn  stones  varying  from 
6  to  12  feet  in  length,  and  still  exhibiting  a  sharp  edge  and  every  mark 
of  the  chisel.  These  rise  into  a  ponderous  wall  immediately  above  the  vents 
which  regulated  the  escape  of  the  water;  and  each  layer  of  the  work  is 
kept  in  its  place  by  the  frequent  insertion,  endwise,  of  long  plinths  of 

274 


EARTHEN  DAMS. 


275 


stone^  whose  extremities  project  beyond  the  surface,  with  a  flange  to  key 
the  several  courses  and  prevent  them  from  being  forced  out  of  their  places. 
The  ends  of  the  retaining-stones  are  carved  with  elephants'  heads  and 
other  devices,  like  the  extremities  of  Gothic  corbels;  and  numbers  of 
similarly  sculptured  blocks  are  lying  about  in  every  direction.  .  .  .  On 
top  of  the  great  embankment  itself,  and  close  by  the  breach,  there  stands  a 
tall  sculptured  stone  with  two  engraved  compartments,  the  possible  record 
of  its  history,  but  the  characters  were  in  some  language  no  longer  under- 
stood by  the  people.  The  command  of  labor  must  have  been  extraordinary 
at  the  time  when  such  a  construction  was  successfully  carried  out,  and  the 
population  enormous  to  whose  use  it  was  adapted.  The  number  of  cubic 
yards  in  the  bund  is  upwards  of  17,000,000,  and  at  the  ordinary  value  of 
labor  in  this  country  [England]  it  must  have  cost  £1,300,000,  without 
including  the  stone  facing  on  the  inner  side  of  the  bank.  The  same  sum 
of  money  that  would  be  absorbed  in  making  the  embankment  of  Padavil 
would  be  sufficient  to  form  an  English  railway  120  miles  long,  and  its 
completion  would  occupy  10,000  men  for  more  than  five  years.  Be  it 
remembered,  too,  that  in  addition  to  30  of  these  immense  reservoirs  in 
Ceylon,  there  are  from  500  to  700  smaller  tanks  in  ruins,  but  many  still 
in  serviceable  order,  and  all  susceptible  of  effectual  restoration.  .  .  .  None 
of  the  great  reservoirs  of  Ceylon  have  attracted  so  much  attention  as  the 
stupendous  work  of  the  Giants'  Tank  (Kattucarre).  The  retaining-bund 
of  the  reservoir,  which  is  300  feet  broad  at  the  base,  can  be  traced  for  more 
than  15  miles,  and,  as  the  country  is  level,  the  area  which  its  waters  were 
intended  to  cover  would  have  been  nearly  equal  to  that  of  Lake  Geneva, 
Switzerland  (223  square  miles).  At  the  present  day  the  bed  of  the  tank 
is  the  site  of  ten  populous  villages,  and  of  eight  which  are  now  deserted." 

It  was  but  recently  discovered  that  the  reason  why  the  great  reservoir 
was  never  utilized  after  having  been  built  at  such  enormous  expense,  was 
an  error  in  the  original  levels  by  which  the  canal  from  the  Malwatte  Eiver, 
that  was  intended  to  feed  the  reservoir,  ran  up-hill. 

Capt.  R.  Baird  Smith,  in  his  work  on  "Irrigation  in  the  Madras 
Provinces,"  says: 

''  The  extent  to  which  tank  irrigation  has  been  developed  in  the  Madras 
Presidency  is  extraordinary.  An  imperfect  record  of  the  number  of  tanks 
in  fourteen  districts  shows  them  to  amount  to  no  less  than  43,000  in  repair 
and  10,000  out  of  repair,  or  53,000  in  all.  It  would  be  a  moderate  esti- 
mate to  fix  the  length  of  embankment  for  each  at  half  a  mile,  and  the 
number  of  masonry  works  in  sluices,  waste-weirs,  etc.,  would  probably  not 
be  overrated  at  an  average  of  six.  These  data,  only  assumed  to  give  some 
definite  idea  of  the  system,  would  give  close  upon  30,000  miles  of  embank- 
ments (sufficient  to  put  a  girdle  round  the  globe  not  less  than  6  feet  thick) 
and  300,000  separate  masonry  works.    The  whole  of  this  gigantic  ma- 


EARTHEN  DAMS. 


277 


chinery  is  of  purely  native  origin^  not  one  new  tank  having  been  made 
by  the  English.  The  revenue  from  existing  works  is  roughly  estimated 
at  £1,500,000  sterling  per  annum,  and  the  capital  sunk  at  £15,000,000." 

The  same  author  described  the  Ponairy  tank  of  Trichinopoly,  now  out 
of  repair,  as  having  an  embankment  30  miles  in  length,  and  an  area  of 
60  or  80  square  miles.  The  Veeranum  tank  is  very  ancient,  though  still 
in  service  and  yielding  a  revenue  of  $57,500  per  annum.  It  has  an  em- 
bankment 12  miles  long,  and  covers  35  square  miles  of  area. 

The  Chumbrumbaukum  tank  has  an  embankment  19,200  feet  in  length, 
and  forms  a  reservoir  of  5730  acres,  with  a  capacity  of  63,780  acre-feet. 
The  dam  is  16  to  28  feet  high.  The  water  from  the  reservoir  yielded  an 
annual  revenue  to  the  government  of  $25,000  in  1853. 

The  Cauverypauk  tank,  in  use  from  four  hundred  to  five  hundred  years, 
has  an  embankment  3f  miles  long,  revetted  with  a  stone  wall  6  feet  thick 
at  bottom,  3  feet  at  top,  and  22  feet  high,  rising  to  within  5  or  6  feet  of  the 
top  of  the  bank,  which  is  uniformly  9  feet  high  above  high-water  mark. 
The  embankment  is  nowhere  less  than  12  feet  wide  on  top,  with  a  front 
slope  of  2\  to  1,  and  a  rear  slope  of  1^  to  1.  The  whole  outer  surface  is 
carefully  turfed  and  planted  with  grass.  Water  is  distributed  from  nine 
masonry  sluices. 

Mr.  H.  M.  Wilson,  in  his  work  on  "  Irrigation  in  India,"  describes  the 
abandoned  tank  of  Mudduk  Masur  as  having  been  built  over  four  hundred 
years  ago,  when  its  capacity  must  have  been  870,000  acre-feet  of  water. 
The  restraining-dams  were  three  in  number;  the  main  central  dam,  which 
is  91  to  108  feet  high,  and  having  a  base  of  945  to  1100  feet,  is  still  intact, 
and  the  whole  reservoir  is  capable  of  easy  restoration.  The  lack  of  a  spill- 
way caused  the  destruction  of  the  tank  by  the  overtopping  of  one  of  the 
minor  embankments.  Mr.  Wilson  states  that  in  the  Mysore  district  of 
southern  India  there  are  37,000  tanks,  aside  from  the  53,000  enumerated 
in  the  Madras  Presidency  by  Capt.  R.  Baird  Smith.  In  the  Mairwara 
District  2065  tanks  have  been  built  under  English  rule  since  the  date  of 
Capt.  Smith's  work,  before  quoted — 1854. 

Of  the  modern  earthen  dams  built  by  English  engineers  in  the  employ 
of  the  Indian  Government,  two  of  the  most  interesting  were  recently  con- 
structed in  the  Bombay  Presidency,  the  Ekruk  tank  near  Sholapur,  and 
the  Ashti  tank,  on  the  Ashti  River.  The  Ekruk  tank  (Fig.  126)  impounds 
76,130  acre-feet,  and  has  a  dam  whose  maximum  height  is  72  feet.  The 
total  length  is  7200  feet,  which  included  2730  feet  of  masonry,  of  which 
1400  feet  is  at  the  northern  end  and  1330  feet  at  the  southern  end.  The 
cost  of  the  dam  was  $666,000.  The  loss  of  water  by  evaporation  during 
eight  months  is  7  feet  in  depth  and  amounts  to  12,500  acre-feet,  or  16% 
of  the  entire  capacity. 

The  Ashti  tank  (Fig.  127)  is  formed  by  an  earth  dam  12,709  feet  long, 


EARTHEN  DAMS. 


279 


58  feet  in  maximum  height^  having  slopes  of  3  :  1  inside  and  2  :  1  outside. 
The  crest  of  the  dam  is  12  feet  above  high-water  mark,  and  has  a  width 
of  6  feet.  The  interior  slope  is  paved  with  stone.  The  storage  capacity 
of  the  reservoir  is  32,660  acre-feet,  of  which  9200  acre-feet,  or  28%,  is 
lost  by  evaporation.  The  reservoir  has  a  surface  area  of  2677  acres.  The 
following  description  of  the  construction  of  the  dam  is  condensed  from 
Mr.  H.  M.  Wilson's  '^Irrigation  in  India": 

The  site  of  the  dam  was  cleared  of  vegetation  and  top  soil,  so  that 
the  entire  structure  rests  upon  a  sound  and  firm  foundation.  There  is  no 
puddle-wall  proper,  but  a  puddle-trench,  10  feet  wide,  was  excavated  down 
to  a  compact,  impervious  bed,  the  entire  length  of  the  dam,  and  was  filled 
to  one  foot  above  the  natural  ground  surface.  This  filling  was  composed 
of  two  parts  sand  and  three  parts  black  soil.  The  central  third  of  the 
dam  is  built  up  of  selected  material  of  black  soil,  extending,  as  shown  in 
the  accompanying  section,  in  a  triangular  section,  60  feet  wide  at  the  base, 
to  the  crest  of  the  dam.  Outside  of  this  central  section  are  two  triangular 
sections  of  brown  soil,  faced  with  1  to  15  feet  of  puddle  of  sand  and  black 
soil.  On  the  inside  a  stone  paving  6  inches  thick  is  laid  over  the  slope  to 
resist  wave-action.  Across  the  river-bed  a  trench  5  feet  wide  was  excavated 
along  the  entire  length  of  the  dam  and  extending  100  feet  into  the  banks. 
On  each  side  this  trench  was  filled  with  concrete  and  connected  with  the 
puddle-trench.  The  puddle-trench  was  curved  around  the  concrete  wall 
and  continued  across  the  river  at  a  distance  of  20  feet  from  the  concrete 
wall  on  the  up-stream  side.  This  work  having  been  finished  in  dry  weather,, 
the  sand  of  the  river-bed  was  sluiced  out  of  the  way  by  confining  the 
stream  and  directing  it  into  narrow  channels  by  loose  rock  spur-walls  and 
piers. 

The  cross-section  of  the  Ashti  dam  is  considered  amply  strong,  yet  a 
more  liberal  section  is  believed  to  be  advisable,  especially  in  the  matter 
of  top  width. 

The  wasteway  of  the  Ashti  reservoir  consists  of  a  channel  800  feet 
wide,  cut  through  the  ridge  rock,  the  crest  of  which  is  level  for  600  feet 
in  length;  thence  the  stream  falls  with  a  slope  of  1%  into  a  side  channel. 
Its  discharging  capacity  is  48,000  second-feet,  causing  the  water  to  rise 
7  feet  above  its  sill,  or  to  within  5  feet  of  the  top  of  the  dam. 

In  1883  a  serious  slip  occurred  in  the  Ashti  dam,  causing  a  total  settle- 
ment of  16  feet  at  the  crest  of  the  embankment,  and  causing  the  ground 
at  the  top  of  the  dam  to  bulge  upwards.  The  cause  of  this  slip  was 
attributed  to  the  fact  that  for  a  considerable  portion  of  the  length  of  the 
dam  it  is  founded  on  a  clay  soil  containing  nodules  of  impure  lime  and 
alkali,  which  render  it  semi-fluid  when  soaked  with  water.  The  slip 
occurred  during  or  after  excessive  rains.  It  was  corrected  by  digging 
drainage-trenches  at  the  rear  toe,  which  were  filled  with  bowlders  and 


280         llESFJiVOmS  FOB  IBlilOATION,  WATEli-FOWEE,  ETC. 

broken  stone,  and  by  the  addition  of  heavy  berms  or  counterforts  of  earth, 
for  700  or  800  feet  of  its  length,  to  weight  the  toe. 

Similar  slips  occurred  in  the  Elcruk  dam,  due  to  similar  causes.  These 
occurrences  point  to  the  value  of  thorough  drainage  to  the  outer  toe  of  all 
earthen  dams,  and  the  desirability  of  the  adoption  of  that  form  of  combma- 
tion  of  rock-flll  and  earth  used  so  successfully  in  the  Pecos  dams,  wherever 
rock  can  be  obtained  for  the  outer  portion  of  such  embankments. 

Vallejo  Dam,  California.— Wherever  earthen  dams  are  constructed 
partially  upon  exposed  bed-rock  foundations,  it  is  essential  to  provide  free 
drainage  to  the  water  which  seeks  to  follow  along  the  bed-rock.  An  inter- 
esting application  of  this  principle  was  made  in  the  construction  of  a  dam 
erected  a  few  years  since  for  the  water-supply  of  Vallejo,  California. 
The  dam  was  built  for  storage  purposes  and  formed  a  reservoir  of  160  acres, 
3  miles  from  the  city.  Thd  bed-rock  was  exposed  in  the  channel,  and 
formed  a  low  fall  about  the  center  line  of  the  dam.  Just  above  this  fall 
a  concrete  wall  was  built  upon  the  bed-rock  some  6  feet  high,  with  a 
drainage-pipe  extending  out  to  the  lower  toe  of  the  embankment.  A 
quantity  of  broken  stone  was  placed  above  this  wall,  which  formed  a 
collecting-basin  for  any  seepage  that  might  pass  through  the  embankment 
or  that  might  creep  along  bed-rock,-  and  the  dam  was  then  built  over  the 
wall  in  the  ordinary  way.  This  provision  effectually  prevents  the  satura- 
tion of  the  outer  slope  and  keeps  the  dam  well  drained.  The  dam  was 
planned  and  built  by  Hubert  Yischer,  C.E.,  with  Mr.  C.  E.  Grunsky 
acting  as  Consulting  Engineer. 

Earthen  dams  are  usually  constructed  in  one  of  the  following  ways: 

(1)  A  homogeneous  embankment  of  earth,  in  which  all  of  the  material 

is  alike  throughout; 

(2)  An  embankment  in  which  there  is  a  central  core  of  puddle  con- 
sisting either  of  specially  selected  natural  materials  found  on  the  site 
or  of  a  concrete  of  clay,  sand,  and  gravel,  mixed  together  m  a  pug-mill 
and  rammed  or  rolled  into  position; 

(3)  An  embankment  in  which  the  central  core  is  a  wall  of  masonry  or 

concrete  * 

(4)  An  embankment  having  puddle  or  selected  material  placed  upon  its 

(5)  An  embankment  of  earth  resting  against  an  embankment  of  loose 

""""'^(G)  An  embankment  of  earth,  sand,  and  gravel,  sluiced  into  position  by 
flowing  water-a  form  of  construction  described  in  the  chapter  on  Hy- 
draulic-fill Dams.  Earthen  dams  have  also  been  built  with  a  facing  of 
plank,  made  water-tight  by  preparations  of  asphaltum  or  tar  The  choice 
of  these  various  available  plans  is  dependent  upon  local  conditions  at  the 
site  of  the  dam  to  be  built,  the  materials  available,  and  the  predilection  or 
education  of  the  engineer  planning  the  structure. 


EABTHEN  DAMS. 


281 


European  engineers,  judging  from  their  works,  lean  toward  the  central 
puddle-core,  and  the  greater  number  of  the  earth  dams  of  the  British 
Empire  are  constructed  on  this  plan.  American  engineers  appear  to  prefer 
the  masonry  core-wall,  or  the  puddle  facing  on  the  inner  slope  of  the 
embankment  to  the  central  puddle-core,  as  a  means  of  cutting  off  per- 
colation through  the  dam  and  thus  securing  water-tightness. 

The  natural  slope  of  dry  earth  placed  in  embankment  is  about  IJ  to  1, 
but  in  practice  it  is  customary  to  increase  this  to  2  to  1  on  the  exterior, 
and  to  3  to  1  on  the  interior  slopes.  The  necessary  height  of  the  em- 
bankment above  the  high-water  mark  depends  to  some  extent  upon  the 
length  and  size  of  the  reservoir,  and  the  reach  "  of  the  waves  generated 
by  winds,  as  well  as  upon  the  width  of  the  spillway  and  the  height  to  which 
water  must  rise  in  the  reservoir  during  maximum  floods  to  find  full  dis- 
charge through  the  spillway.  Ample  spillway  capacity  is  of  primary  im- 
portance to  the  security  of  any  earthen  dam,  unless  it  be  one  whose  reser- 
voir is  filled  by  a  canal  or  other  controllable  conduit  from  an  adjacent 
stream.  A  lack  of  sufficient  spillway  is  the  cause  of  the  greater  number 
of  the  failures  of  earthen  dams  that  have  occurred,  of  which  the  most 
memorable  case  was  that  of  the  Johnstown  dam,  whose  rupture  caused  the 
loss  of  two  thousand  lives  and  the  destruction  of  many  millions  of  dollars' 
worth  of  property.  Had  the  spillway  been  ot  ample  dimensions,  this  dam 
would  have  resisted  any  pressure  that  could  have  been  brought  to  bear 
upon  it  and  the  disaster  would,  in  all  probability,  never  have  occurred. 

A  common  source  of  failure  is  in  the  doubtful  practice  of  building  the 
outlet-pipes  through  the  body  of  the  dam.  These  should  either  be  laid  in 
a  tunnel  at  one  side,  or  in  a  deep  trench  cut  into  the  bed-rock  or  the 
solid  impervious  base  of  the  dam,  and  the  pipes  surrounded  by  concrete, 
filling  the  entire  trench. 

In  building  earth  dams  of  any  type  it  is  essential  that  the  earth  should 
be  moist  in  order  to  pack  solidly,  and  if  not  naturally  moist  it  must  be 
sprinkled  slightly  until  it  acquires  the  proper  consistency.  An  excess  of 
moisture  is  detrimental.  It  should  be  placed  in  thin  layers,  and  thor- 
oughly rolled  or  tamped,  and  the  surface  of  each  layer  should  be  rough- 
ened by  harrowing  or  plowing  before  the  next  layer  is  applied.  Droves  of 
cattle,  sheep,  or  goats  are  often  used  with  success  as  tamping-machines  for 
earth  embankments.  They  are  led  or  driven  across  the  fresh  made  ground, 
and  the  innumerable  blows  of  their  sharp  hoofs  pack  the  soil  very  thor- 
ou,2"hlv. 

The  Cuyamaca  Dam.— One  of  the  first  earthen  dams  built  in  California 
for  irrigation  storage  was  the  Cuyamaca  reservoir-dam,  erected  in  1886 
by  the  San  Diego  Flume  Company.  It  is  located  in  a  summit  valley 
between  two  of  the  Cuyamaca  peaks,  some  50  miles  east  of  San  Diego,  at 
an  elevation  of  4800  feet.    The  dam  is  635  feet  long  on  top,  41.5  feet  high. 


282         RESERVOmS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


with  iniuT  ylo})c  ol'  2  :  1,  and  outej'  slope  of  1.5  :  1.  The  crest  of  tlie  dam 
is  6.5  feet  above  the  iloor  of  tlie  spillways^,  one  of  which  is  DO  feet  and 
the  other  41  feet  in  width. 

Before  work  was  begun  on  the  dam  the  site  was  covered  with  loose 
rock^  and  it  was  supposed  that  bed-rock  was  near  the  surface.  Hence  the 
original  plan  was  to  build  a  masonry  dam.  Excavations  were  started  for 
that  purpose,  and  considerable  cement  was  brought  to  the  ground  to 
construct  the  foundations  of  masonry.  It  was  soon  found,  however,  that 
the  loose  rock  was  merely  a  surface  layer  on  top  of  a  bed  of  clay,  and 
the  plan  was  changed  to  a  dam  of  earth  throughout. 

The  discharge-sluice  of  the  dam  was  built  through  the  center  of 
the  structure,  and  consisted  of  a  masonry  culvert  3^  feet  wide,  4^  feet 
high,  120  feet  long,  resting  on  a  bed  of  concrete  18  inches  thick,  laid 
in  a  trench  of  that  depth  but  in  the  clay.  This  culvert  has  a  fall  of 
3^  feet  in  length.  At  its  upper  end  is  a  circular  brick  tower,  5  feet  in 
diameter  inside,  with  an  opening  at  the  bottom  3  feet  wide,  4|-  feet 
high,  that  is  closed  by  a  ponderous  wooden  gate,  so  large  and  heavy  as  to  be 
almost  immovable.  A  second  gate,  16  feet  higher,  of  similar  size  and 
construction,  is  provided  to  close  another  opening  into  the  tower.  These 


Fig.  128.— View  of  Cuyamaca  Dam  and  Outlet- tower. 


gates  slide  vertically  in  wooden  grooves.  An  iron  gate  inside  the  tower 
closes  the  head  of  the  culvert. 

The  bond  between  the  earthwork  and  the  culvert  was  imperfect,  and 
considerable  leakage  ensued  after  the  reservoir  first  filled,  but  this  was 
afterwards  remedied. 

Fig.  128  is  a  view  of  the  dam  from  the  side  of  the  reservoir,  showing 
the  tower. 

The  dam  is  reported  to  have  cost  $51,000  as  originally  constructed  to 
the  height  of  35  feet.  In  1894  an  addition  of  6.5  feet  was  made  to  the 
height  of  the  dam,  at  a  cost  of  $3400.  This  addition  increased  the  capacity 


EARTHEN  DAMS. 


285 


of  the  reservoir  to  11,410  acre-feet,  covering  an  area  of  959  acres  to  a  mean 
depth  of  nearly  12  feet.  The  watershed  tributary  to  the  reservoir  is  about 
11  square  miles.  The  following  table,  prepared  by  Mr.  F.  S.  Hyde,  C.E., 
from  the  records  of  the  company  in  1896,  gives  the  volume  of  catchment 
and  use  during  the  first  nine  years  after  the  completion  of  the  dam: 

Table  of  Rainfall,  Run  off,  Evaporation  and  Average  Draft  from  the 
CuYAMACA  Reservoir,  San  Diego  County,  California. 


Calendar 
Year. 

Rain  and 
Melted 
Snow. 

Inches. 

Run-off  in 
Acre-feet. 

Percentage 
of  Run-off 
to  Precipita- 
tion. 
Per  cent. 

Run-off 
per 
Square  Mile. 
Second-feet. 

Evaporation. 

Average 
Draft  from 
Reservoir 

for 
Irrigation 
and 
City  Supply. 
Acre-feet. 

Total. 
Ft.  In. 

Average 
per  Day. 
Inches. 

1888 
1889 
1890 
1891 
1893 
1893 
1894 
1895 
1896 

Means  .. 

24.05 
52.83 
62.91 
64.96 
42.56 
41.51 
24.90 
58.52 
26.44 

3,076 
5,568 
6.214 
7,735 
5,163 
4,098 
2,035 
11,464 
1,158 

21.75 
17.91 
16.79 
20.24 
20.62 
16.78 
13.89 
33.31 
7.45 

0.385 
0.697 
0.768 
0.969 
0.647 
0.512 
0.255 
1.436 
0.145 

3  9.50 

4  5.00 
3  9.25 
3  8.75 
3  6.75 

5  3.25 
7  1.00 
5  3.75 
5  7.50 

0.316 
0.250 
0.208 
0.203 
0.241 
0.303 
0.341 
0.317 
0.284 

2,853 
3,881 
3,084 
4,821 
5,965 
2,939 
6,237 
5,777 

44.29 

5,397 

19.83 

0.676 

4  8.75 

4,331 

Subsequent  years  of  drouth  have  resulted  in  emptying  the  reservoir 
entirely.  The  rainy  seasons  of  1897-98,  1898-99;-^  and  1899-1900  have 
furnished  practically  no  water  for  storage. 

Eeferring  to  the  above  table  of  rainfall  and  run-off,  it  should  be  ex- 
plained that  as  the  rain-gauge  on  which  the  precipitation  was  recorded 
is  located  at  the  dam  between  two  high,  wooded  peaks,  which  act  as 
condensers  of  the  moisture-laden  clouds,  the  record  shows  a  greater  amount 
than  the  average  of  the  watershed,  which  a  few  miles  east  of  the  dam 
borders  on  the  desert,  where  the  rainfall  is  known  to  be  much  less.  This 
is  borne  out  by  comparing  the  measured  run-off  with  the  "  Newell  Curve  " 
of  run-off,  which  would  indicate  that  if  the  recorded  precipitation  were 
a  mean  of  the  entire  area,  the  yield  should  be  two  to  three  times  as  great 
as  it  actually  was.  This  Cuyamaca  rainfall  record  is  misleading  as  a 
criterion  of  mountain  precipitation  in  this  region.  The  water  actually 
flowing  in  different  seasons  from  a  known  area,  as  shown  by  the  table,  is 
more  reliable  as  a  guide  for  estimates  of  the  yield  to  be  expected  from 
adjacent  sheds  than  any  single  rainfall  record,  or  any  possible  collection 
of  rainfall  statistics  without  such  empirical  knowledge  of  actual  yield  in 
stream-flow  produced  by  any  given  rainfall. 

During  the  period  covered  by  the  table  the  mean  annual  draft  from  the 


JiESmiVO/IiS  FOR  JIUIIGATION,   WATER  POWER,  ETC. 


resorvoir  was  \\V,]\  acrc-reci,  while  iJie  mean  annual  I'liii-olT  was  T),']!)?  acre- 
feet.  The  (lilTerenee  between  these  iigures,  or  10(i(5  aere-fciet,  represents 
the  mean  annual  evaporation,  or  ID. 75  per  cent  of  total  catchment. 

After  llowino-  down  Bowlder  Creek  and  the  KSan  Diego  lliver  miles, 
dropping  ^000  feet  vertically  in  that  distance,  the  water  released  at  the 
dam  is  picked  up  and  diverted  to  the  flume  hy  means  of  a  masonry  weir 
extending  across  the  San  Diego  liiver.  This  diverting-dam  is  340  feet  long 
on  top,  35  feet  high,  22  feet  thick  at  base,  5  feet  at  the  crest.  To  cut  oil; 
leakage  under  the  dam  a  subwall  was  built  on  the  up-stream  side  in  the 
main  channel,  lapping  onto  the  base  of  the  dam  and  extending  down  15 
feet  deeper.  This  wall  is  5  feet  thick  at  bottom.  The  original  wall  had 
been  founded  on  disintegrated  granite.  The  subwall  was  built  in  a  trench 
that  cut  deeper  into  the  soft  granite,  but  was  not  entirely  effectual  in 
stopping  the  leakage.    (Figs.  129  and  130.) 


Fig.  130. — Plan  and  Elevation  o.p  Diverting-dam  op  San  Diego  Flume  Co., 

California. 


The  main  flume  is  34.85  miles  in  length,  6  feet  wide  in  the  clear,  with 
single  sideboards  16  inches  high,  though  the  frame-posts  are  4  feet  high 
and  will  admit  of  additional  sideboards  to  give  a  total  depth  of  4  feet.  If 
completed  as  originally  designed,  the  flume  would  have  a  capacity  of  5000 
miner's  inches  under  4-inch  pressure.  Its  present  maximum  capacity  is 
not  over  900  inches.  The  flume  is  supported  at  places  on  high  trestles, 
one  of  which  is  shown  in  Fig.  131,  and  there  are  a  number  of  long  and 
costly  tunnels  on  the  route.  The  grade  of  the  flume  is  4.75  feet  per  mile. 
It  commands  all  the  irrigable  lands  of  El  Cajon  Valley,  Spring  Valley,  and 
the  San  Diego  mesa,  and  supplies  water  to  about  5700  acres,  mostly  culti- 
vated in  orchards  of  citrus  fruits.   The  city  of  San  Diego  has  also  received 


Of  TWE 
OHlV£RS[TYaf1LUN0U 


EARTHEN  DAMS. 


289 


its  domestic  supply  from  this  source  during  the  greater  portion  of  the  time 
since  its  completion,  through  a  15-inch  steel-pipe  line  laid  over  the  mesa, 
from  the  end  of  the  flume  to  the  city,  about  10  miles. 

In  the  summer  of  1897-98  the  reservoir  was  quickly  exhausted,  and  it 
became  necessary  to  install  an  independent  system  of  supply  for  the 
orchards  and  the  city  of  San  Diego.    For  the  orchard  supply  this  was 
accomplished  by  sinking  a  series  of  bored  wells  in  the  gravel  bed  of  the 
San  Diego  River,  above  El  Cajon  Valley,  where  the  flume  leaves  the 
immediate  valley  of  the  river.    Pumping-stations  were  erected,  and  the 
wells,  which  were  placed  at  intervals  of  50  feet  along  a  horizontal  suction- 
pipe  1000  to  1300  feet  in  length,  were  drawn  upon  in  series  simultaneously, 
the  water  being  forced  up  to  the  flume  with  a  lift  of  300  feet.    About  3 
second-feet  (150  inches)  were  thus  obtained,  and  though  the  supply  was 
meager  it  was  sufficient  to  maintain  the  life  of  the  trees  and  keep  them 
in  bearing  with  good  cultivation.    The  city  was  supplied  in  a  similar 
manner  by  wells  sunk  in  the  river-bed  in  Mission  Valley,  from  2  to  4  miles 
above  the  main  pumping-plant.   The  water  was  lifted  to  the  surface  at  sev- 
eral points  and  conveyed  to  the  pump-station  by  small  flumes.  Over 
3,000,000  gallons  daily  were  thus  ,  obtained.    These  plants  have  had  to  be 
maintained  and  increased  in  capacity  oip  to  the  present  writing  ^( April, 
1900),  with  a  prospect  of  continuance  until  the  fct  rainy  season.   The  in- 
habitants of  southern  California  have  reason  to  congratulate  themselves 
that  Nature  has  provided  underground  storage-reservoirs  capable  of  being 
drawn  upon  so  liberally  that  they  are  able  to  endure  such  an  unprecedented 
period  of  drouth  as  they  are  now  experiencing.    To  obtain  the  supply, 
however,  by  wells  and  pumps  is  generally  far  more  costly  than  water  stored 
in  surface  reservoirs. 

The  Merced  Reservoir  Dam,  California.— The  highest  and  longest 
earthen  dam  closing  a  reservoir  chiefly  devoted  to  irrigation  in  California 
is  that  which  forms  the  so-called  "  Yosemite  Reservoir,"  6  miles  north- 
east of  the  town  of  Merced.  This  dam  was  constructed  in  1883-84  by  the 
Crocker-Hoflman  Land  Company  as  a  part  of  its  general  system  of  irriga- 
tion, by  which  some  150,000  acres  are  commanded  for  irrigation.  It  has 
a  maximum  height  of  50  feet,  and  is  built  entirely  of  earth  composed  of  a 
sandy  clay  with  inner  slopes  of  3  :  1  and  outer  slopes  of  2  : 1.  From  the 
top  down  for  15  feet  the  interior  is  paved  with  loose  rock,  12  inches  thick, 
for  wave-protection.  The  entire  length  of  the  dam  is  2200  feet,  of  which 
1400  feet  is  less  than  10  feet  high.  It  was  built  up  as  a  homogeneous  bank 
of  earth,  without  a  puddle-wall,  or  without  adding  to  the  natural  moisture 
of  the  soil.  The  earth  was  simply  put  in  place  with  scraper-teams,  the 
material  being  deposited  with  care  in  thin  layers.  The  top  width  is  20  feet, 
base  290  feet.  The  dam  rests  on  a  very  firm  foundation  of  cemented 
gravel,  into  which  a  wide,  deep  puddle-trench  was  cut  and  carefully  re- 


290         EESEUVOIliS  FOR  HUUGATION,  WATKli-POWER,  ETC. 


Fig.  131a. — Map  showing  Location  of  Mekced  Resekvoie,  California. 


EABIHEN  DAMS. 


293 


filled.    Much  of  the  material  used  in  the  dam  had  to  be  loosened  by 

^^^T^f  reservoir-outlet  consists  of  a  masonry  conduit,  made  of  brick  laid 
in  cement  mortar,  placed  in  a  trench  cut  in  the  cemented  gravel.  This 
conduit  carries  the  main,  cast-iron,  delivery-pipe,  24  inches  in  diameter, 
and  a  blow-off  sluice-pipe.  The  conduit  is  4  feet  in  diameter  m  the  clear, 
the  brickwork  being  12  inches  in  thickness. 

The  reservoir,  dam,  and  outlet-tower  are  shown  in  Fig.  132. 
The  reservoir  covers  600  acres  and  has  a  capacity  when  full  of  15,000 
acre-feet  of  which  about  20%  is  annually  lost  by  evaporation.  It  is  fed 
by  a  canal  27  miles  in  length,  leading  from  a  diversion-weir  placed  m  tlie 
Merced  River  a  short  distance  above  the  town  of  Snellmg.  For  the  hrst  8 
miles  the  canal  has  a  maximum  capacity  of  1500  second-feet,  which  is  the 
largest  canal  in  California.  The  total  cost  of  the  canal  system,  with  its 
laterals,  and  the  reservoir  was  about  $1,500,000. 

The  watershed  area  of  the  Merced  River  above  the  head  of  the  canal  is 
1076  square  miles,  in  which  is  included  the  famous  Yosemite  Valley.  The 
mean  annual  flow  of  this  stream  as  determined  by  the  Cahforma  State 
Engineering  Department  for  the  six  years,  irom  1878  to  1884  was  about 
1600  second-feet,  the  maximum  being  6510  second-feet  in  the  month  of 
June,  and  the  minimum  65  second-feet  in  the  months  of  November  and 
December.  During  the  three  months  of  May,  June,  and  July,  when  the 
greatest  amount  of  irrigation  is  required,  the  mean  discharge  of  the  river 
in  the  period  named  was  about  4000  second-feet. 

Buena  Vista  Lake  Reservoir,  California.— The  large  storage-tank 
formed  of  Buena  Vista  Lake,  in  the  southern  end  of  the  San  Joaquin 
Valley,  is  the  largest  irrigation-reservoir  in  the  State,  covering  an  area  of 
25,OOo' acres  to  a  mean  depth  of  nearly  7  feet.  The  volume  of  water  which 
it  is  capable  of  impounding  above  the  level  of  the  outlet-canal  is  170,000 
acre-feet,  and  in  its  general  characteristics  it  more  nearly  resembles  the 
great  tanks  of  India  than  any  reservoir  in  this  country. 

The  reservoir  is  formed  by  a  straight  dike,  or  dam,  5.5  miles  in  length, 
following  a  township  line  from  the  foot-hills  at  the  base  of  the  mountains, 
due  north.  The  maximum  height  of  the  dam  is  15  feet,  tapering  out  to 
nothing  at  either  end.  Its  top  width  is  12  feet,  and  the  slopes  are  4 : 1 
inside,  3  : 1  outside,  the  crest  being  4  feet  higher  than  the  high-water  level 
of  the  reservoir  when  full.  The  erosion  of  this  bank  due  to  wave-action 
rendered  it  necessary  to  riprap  the  face  with  stone  over  a  long  section 
from  the  south  end  northward,  where  there  were  no  tules  growing  to  serve 
as  a  breakwater  to  lessen  the  effect  of  wave-action,  as  was  the  case  at  the 
north  end.  To  procure  the  material  for  this  riprap  a  narrow-gauge  rail- 
road was  built  for  some  ten  miles  from  a  quarry  at  the  base  of  the  moun- 
tains.   The  cost  of  this  work  was  more  expensive  than  the  construction 


29-J:         IIESERVOIIIS  FOIl  imUGATIOJY,  WATEli-POWKIl,  ETC. 

of  the  enibankineiit  and  brought  the  entire  cost  of  the  dam  and  outlets  up 
to  al)out  $150^000.  Tlie  dam  divides  the  reservoir  from  what  was  formerly 
known  as  Kern  Lake,  before  its  bed  was  drained  and  cultivated. 

Tiie  reservoir  now  receives  all  the  sur})lus  water  of  Kern  lliver  and  the 
waste  at  the  tail  end  of  all  of  the  Kern  Island  canals  below  Bakersfield. 
The  water  thus  stored  is  only  available  for  use  on  a  belt  of  arable  land 
that  was  formerly  a  swamp,  extending  from  Buena  Vista  Lake  to  Tulare 
Lake.  This  land  before  reclamation  was  periodically  overflowed  when 
the  water  of  the  river  was  not  so  extensively  absorbed  in  irrigation  in 
the  delta  and  upon  the  adjacent  plains  as  it  has  been  in  recent  years. 
Since  its  reclamation  it  requires  to  be  irrigated,  and  the  reservoired  water 
is  devoted  to  that  purpose. 

The  reservoir  was  first  filled  in  1890,  and  has  been  in  service  ever  since. 
Its  creation  was  the  result  of  the  compromise  of  the  most  extensive  and 
costly  litigation  over  water-rights  that  has  ever  arisen  in  California.  The 
title  of  the  action  was  that  of  Lux  vs.  Haggin.  It  will  go  down  in  history 
as  the  case  in  which  the  Supreme  Court  of  California,  by  a  majority  of 
one,  first  established  the  English  common-law  doctrine  of  riparian  rights 
as  applicable  to  the  streams  of  the  State.  It  is  believed  that  this  doctrine, 
though  greatly  modified  by  subsequent  decisions,  has  been  a  serious  draw- 
back to  irrigation  development  in  California. 

The  surface  of  the  reservoir  is  so  large  as  compared  with  the  volume 
stored  that  the  annual  loss  by  evaporation  is  estimated  at  120,000  acre-feet, 
or  70%  of  the  total  capacity.  This  is  an  enormous  waste  of  water,  which 
might  be  saved  to  a  considerable  extent  by  the  construction  of  storage- 
reservoirs  in  the  mountains,  where  the  ratio  between  surface  area  and 
volume  would  be  very  much  less,  and  the  rate  of  evaporation  smaller.  The 
reservoir  is  generally  filled  from  about  May  1st  to  July  20th,  during  the 
melting  of  the  snows,  after  which  time  to  September  1st  the  inflow  is 
about  sufficient,  ordinarily,  to  offset  evaporation.  Thus  during  the  five 
hottest  months,  when  nearly  70%  of  the  total  evaporation  of  the  year  takes 
place,  the  loss  is  supplied  by  the  river,  and  by  the  return  waters  of  irriga- 
tion. Therefore,  in  those  seasons  when  the  run-off  is  sufficient  to  supply 
the  demand  of  the  canals  and  yield  a  surplus  great  enough  to  fill  the 
reservoir  by  September  1st,  in  addition  to  evaporation,  the  net  amount 
available  for  use  from  the  reservoir  would  approximate  125,000  to  135,000 
acre-feet.  Measurements  of  the  river  taken  daily  from  1879  to  1884,  and 
from  1894  to  1897,— ten  years  in  all,— show  a  minimum  yearly  discharge 
of  364,000  acre-feet,  a  maximum  of  1,760,000  acre-feet,  and  a  mean  of 
789,000  acre-feet  of  water  discharging  into  the  valley  at  the  mouth  of  the 
nanyon. 

The  Pilarcitos  and  San  Andres  Dams,  California. — The  water-supply 
of  San  Francisco  is  largely  derived  from  the  storage  of  storm-waters  on 


EARTHEN  DAMS, 


295 


the  peninsula  south  of  the  city.  The  San  Mateo  dam,  of  concrete,  described 
in  a  previous  chapter,  supplanted  one  of  the  original  earthen  dams,  that 
known  as  the  Upper  Crystal  Springs;  but  there  are  two  other  notable 
structures  still  in  service,  called  the  Pilarcitos  and  the  San  Andres  dams. 

The  Pilarcitos  dam  is  640  feet  long  on  top,  95  feet  in  height  above  the 
original  surface  of  the  ground,  and  has  a  top  width  of  24  feet.  The  slopes 
are  2  :  1  each  side.  A  puddle-wall,  24  feet  thick,  extends  down  40  feet 
below  the  surface,  into  a  trench  cut  in  bed-rock.  The  reservoir  formed  by 
the  dam  has  a  capacity  of  1,180,000,000  gallons  (3622  acre-feet),  and 
gathers  the  run-off  from  a  watershed  of  2510  acres.  The  elevation  of  the 
lake  is  696  feet  above  sea-level. 

The  San  Andres  dam  has  a  top  length  of  850  feet,  a  maximum  height 
of  93  feet  above  the  original  surface,  and  a  top  width  of  24  feet.  The 
inside  slope  is  3.5:1,  while  the  outer  slope  is  3:1.  The  central  puddle- 
wall  reaches  to  bed-rock  through  46  feet  of  earth  and  gravel.  The  dam 
was  originally  built  to  a  height  of  77  feet,  but  in  1875  it  was  raised  16  feet 
by  the  addition  of  the  new  material  upon  the  outer  slope.  The  base  of  the 
new  section  was  135  feet.  As  the  inner  slope  was  projected  to  the  new 
crest  of  the  dam  it  became  necessary  to  make  a  horizontal  offset  in  the 
puddle-wall  in  order  to  keep  it  within  the  center  of  the  new  section. 

The  San  Andres  reservoir  has  a  capacity  of  6,500,000,000  gallons 
(19,950  acre-feet),  and  intercepts  the  drainage  from  2695  acres  of  water- 
shed immediately  tributary.  It  is  also  fed  by  a  flume,  17.42  miles  in  length, 
leading  from  Lock's  Creek.  This  flume  gathers  the  water  from  1800 
acres  of  the  Lock's  Creek  shed,  all  above  505  feet  elevation.  Other  feeders 
to  the  reservoir  gather  the  water  from  Pilarcitos  Creek  below  the  Pilarcitos 
dam,  and  from  a  branch  of  San  Mateo  Creek. 

Cache  la  Poudre  Reservoir  Dam,  Colorado. — The  Union  Colony  of 
Greeley,  in  northern  Colorado,  is  supplied  with  water  for  irrigation  by  the 
Cache  la  Poudre  Canal,  an  important  adjunct  of  which  is  a  storage-reser- 
voir of  5654  acre-feet  capacity,  formed  by  an  earthen  dam,  38  feet  in 
height.  For  a  long  time  after  the  construction  of  the  canal  it  was  thought 
unnecessary  to  supplement  its  river-supply  by  a  reservoir.  Later  experi- 
ence showed  that  the  low-water  period  came  on  in  many  years  before  the 
potato-crop  was  made,  and  a  reservoir-site  was  sought  to  store  water  to 
carry  the  farmers  over  this  critical  period.  The  site  selected  was  one 
which  could  be  filled  by  a  supply-canal,  8  miles  long,  discharging  into  the 
main  canal  2  miles  below  its  head. 

The  dam  was  made  by  scraper-teams,  of  the  soil  at  the  site,  and  is 
homogeneous  in  character,  without  puddle.  It  was  originally  made  with 
a  uniform  inner  slope  of  more  than  3  to  1,  but  the  action  of  waves  has 
made  it  quite  irregular.  The  embankment  settled  4  to  5  feet  the  first  year 
after  the  water  was  turned  in,  and  becomes  quite  soft  throughout  whenever 


296         RESERVOIRS  FOR  IRRIGATION,  WATER  POWER,  EIC. 

the  reservoir  is  lilled,  but  this  is  yearly  becoming  less.  The  rock  for  rip- 
rapping  the  face  of  the  dam  was  brought  by  rail  to  the  nearest  point,  and 
hauledV  wagon  two  miles,  costing  $1.10  per  ton  laid  down.  The  dam  cost 
$81,623  for  construction,  in  addition  to  $28,643  paid  for  real  estate  and 
rights  of  way— a  total  of  $110,266.  The  year  after  it  was  completed  and 
fined,  the  reservoir  proved  its  value  by  saving  the  crop  of  potatoes  valued 
at  $331,366,  of  which  one-half  is  credited  to  the  reservoir. 

The' feeder-canal  has  a  capacity  of  150  second-feet,  while  the  outlet- 
canal  will  carry  200  second-feet. 

The  outlet-conduit  is  founded  on  tough  clay,  and  has  a  floor  of  wide 
flagstones  laid  on  concrete.  The  conduit  is  5  feet  wide,  and  5  feet  high 
in ''center,  the  side  walls  being  2^  feet  high,  and  a  semicircular  arch  form- 
ing the  roof.  Two  collar-walls  extend  into  the  embankment  to  cut  off 
leakage.  The  gates  are  the  invention  of  Gordon  Land,  a  well-known 
hydraulic  engineer  of  Denver,  and  are  known  as  "  railroad  gates."  They 
are  two  in  number  and  travel  on  a  double  track,  set  at  an  inclination  of 
20°  from  the  vertical,  the  gates  being  provided  with  wheels.  They  go 
down  to  their  seats  by  gravity,  and  are  raised  by  wire  ropes  passing  over 
a  windlass  at  the  top  of  the  embankment. 

Colorado  State  Dams.— In  1892  the  State  of  Colorado  by  legislative 
enactment  inaugurated  a  system  of  storage-reservoirs  for  irrigation,  under 
which  five  dams  were  erected  in  different  parts  of  the  State  by  money 
appropriated  for  the  purpose  by  the  State  legislature.  This  is  a  policy 
which  has  not  been  attempted  by  any  other  of  the  States  of  the  Union, 
so  far  as  the  writer  is  aware,  and  in  this  case  it  does  not  appear  to  have 
been  successful  or  to  meet  with  popular  favor.  The  dams  are  under  the 
control  of  the  State  Engineer,  and  water  from  them  is  sold  to  the  irriga- 
tors. 

The  selection  of  the  sites  and  the  expenditure  of  the  money  appear  to 
have  been  controlled  by  politics  rather  than  by  good  engineering.  The 
experiment  cost  the  State  $102,544.88  in  all,  and  the  total  storage  provided 
was  but  2574  acre-feet  in  the  aggregate.  An  account  of  these  works, 
gleaned  from  the  State  Engineer's  reports,  is  of  interest,  and  is  con- 
densed as  follows:  ^  . 

The  Monument  Creek  Dam.-This  earthen  dam  is  located  on  Monument 
Creek,  some  15  miles  north  of  Colorado  Springs,  at  an  elevation  of  7000 
feet  above  sea-level.   Its  dimensions  are  the  following: 

Maximum  height   40  feet 

Width  on  top  

Length  on  top  

Inner  slope   ^  * 

2*1 

Outer  slope  •  


EARTHEN  DAMS. 


297 


The  water-line  is  7  feet  below  the  crest  of  the  dam.  The  inner  face  of 
the  dam  is  covered  with  a  clay  puddle-wall  laid  on  the  slope,  with  a  hori- 
zontal thickness  of  50  feet  at  the  base  and  10  feet  at  top.  This  puddle  is 
carried  down  to  bed-rock  in  a  trench  14  feet  deep,  at  the  inner  toe  of  the 
dam,  the  minimum  width  of  the  trench  being  5  feet.  Over  the  puddle-wall 
is  laid  a  riprap  wall  of  stone,  placed  with  care  by  hand.  The  outer  half 
of  the  dam  is  composed  of  coarse  gravel,  rock,  and  earth.  These  general 
principles  must  be  regarded  as  unexceptionable  in  earth-dam  construc- 
tion. 

The  reservoir-outlet  is  formed  by  two  16-inch  cast-iron  pipes,  laid  in  a 
trench  excavated  underneath  the  dam,  with  concrete  collars,  12  inches 
wide  and  the  same  thickness,  at  each  of  the  joints.  Between  these  collars 
the  trench  was  filled  with  puddled  clay.  Just  above  the  inner  line  of  the 
crest  of  the  dam  a  gate-tower  is  carried  up  through  the  embankment  from 
the  level  of  the  outlet-pipes.  At  the  bottom  of  this  tower  two  16-inch 
stop-valves  are  placed  in  the  outlet-pipes,  their  stems  reaching  to  the  top 
of  the  dam  inside  the  tower.  The  tower  is  circular  in  form,  4^  feet  inside 
diameter  for  the  lower  8  feet,  and  3  feet  diameter  for  the  remaining 
lieight.  It  is  built  of  sandstone,  18  inches  thick,  laid  in  cement.  The 
entire  tower  is  encased  in  puddled  clay. 

The  spillways  provided  each  side  the  dam  have  a  total  width  of  200 
feet,  although  50  feet  width  was  regarded  as  probably  ample  to  carry  the 
maximum  floods  from  the  22  square  miles  of  drainage-area. 

The  dam  was  planned  and  built  under  the  supervision  of  J.  P.  Maxwell, 
State  Engineer.  The  work  was  done  by  contract  for  $25,000,  exclusive 
of  engineering,  but  when  finally  completed  in  1894  its  entire  cost  had 
reached  $33,121.53.  The  award  of  the  contract  was  made  subject  to  the 
proviso  that  El  Paso  County,  in  which  it  is  located,  should  furnish,  without 
cost  to  the  State,  a  clear  title  to  the  land  required,  which  was  done. 

It  was  estimated  that  the  reservoir  could  be  filled  three  or  four  times 
€very  year,  but  it  is  found  to  fill  once  and  sometimes  twice  in  a  year. 

The  reservoir  covers  62  acres  to  a  mean  depth  of  13.8  feet,  or  42%  of 
the  maximum  depth.   It  impounds  885  acre-feet. 

Tie  Apishapa  State  Dam  is  located  in  the  Metote  Canyon  in  Las  Animas 
County,  and  was  completed  in  1892.  The  dam  is  of  earth,  and  forms  a 
reservoir  of  459  acre-feet  capacity.  Its  cost  was  $14,771.80.  It  is  filled  by 
a  ditch,  2  miles  long,  leading  from  Trujillo  Creek,  which  has  30  square 
miles  of  watershed,  the  water  from  which  is  fully  appropriated  and  used 
loj  prior  locators. 

The  BardscmlUe  State  Bam  is  an  earthen  structure,  completed  by  the 
State  in  1894,  at  a  cost  of  $9997.31.  It  impounds  but  102  acre-feet  of 
water,  and  is  filled  by  a  ditch  from  Hardscrabble  Creek,  in  Custer  County. 

The  Boss  Lake  State  Dam  is  located  in  Chaffee  County,  on  the  head- 


298 


BESERVOIRS  FOR  IRRIGATION,  WATER- POWER,  ETC, 


waters  of  the  South  Arkansas  Kivcr.  It  was  finished  in  1894,  at  a  cost 
of  $14,654.24,  and  forms  a  reservoir  with  a  capacity  of  205  acre-t'eet.  It 
is  made  of  earth,  and  was  reported  to  be  unsafe  in  construction  and  was 
never  filled.    The  tributary  watershed  is  4  square  miles. 

The  Saguache  State  Dam  is  located  near  the  town  of  Saguache,  and  is 
an  earthen  dam  which  cost  $30,000.  The  reservoir  capacity  behind  it  is 
954  acre-feet.  It  is  filled  by  a  ditch  from  the  Saguache  River,  but  as  the 
normal  flow  of  the  stream  is  fully  appropriated,  only  the  winter  and  spring 
floods  are  available. 


CHAPTER  V. 


NATURAL  RESERVOIRS. 

On  the  great  plains  east  of  the  Rocky  Mountains  there  are  thousands 
of  natural  basins  which  have  no  outlets  and  which  gather  the  storm-water 
run-off  from  a  few  hundred  acres  of  surrounding  territory,  and  hold  it  in 
shallow  ponds  until  it  is  lost  by  evaporation.  Many  of  these  depressions 
have  been  utilized  as  storage-reservoirs  by  carrying  water  to  them  from 
adjacent  streams,  and  by  providing  them  with  outlets,  either  by  tunnels 
or  cuts;  and  many  more  have  been  selected  for  future  utilization.  They 
are  often  at  the  proper  elevation  to  command  large  areas  of  arable  land, 
and  can  usually  be  converted  into  safe  storage-reservoirs  at  small  expense. 
Such  natural  basins  appear  to  be  invariably  water-tight,  and  in  every  way 
suitable  to  the  purpose,  except  in  occasional  instances  where  they  contain 
deep  beds  of  alkali. 

The  Alpine  Keservoir,  California. — The  project  of  the  South  Antelope 
Yalley  Irrigation  Company,  completed  in  May,  1896,  and  put  in  service  the 
following  year,  is  dependent  upon  a  reservoir,  formed  in  a  natural  basin,* 
which  has  unusual  features  and  is  of  special  interest,  not  only  as  the 
first  reservoir  of  any  magnitude  completed  on  the  borders  of  the  Mojave 
Desert  in  southern  California,  but  because  it  lies  directly  in  the  line  of 
what  is  known  as  "  the  great  earthquake  crack  "  of  this  region,  which  is 
marked  by  a  series  of  similar  basins  behind  a  distinct  ridge  that  appears 
to  have  been  the  result  of  the  great  seismic  disturbance. 

This  remarkable  line  of  fracture  can  be  traced  for  nearly  200  miles 
through  San  Bernardino,  Los  Angeles,  Kern,  and  San  Luis  Obispo  coun- 
ties, and  deviates  but  slightly  here  and  there  from  a  direct  course  of  about 

60°  W.  There  appears  to  have  been  a  distinct  "  fault "  along  the  line, 
the  portion  lying  south  of  the  line  having  sunken,  and  that  to  the  north 
of  it  being  raised  in  a  well-defined  ridge.  In  many  places  along  the  great 
crack  ponds  and  springs  make  their  appearance,  and  water  can  be  had  in 
wells  at  little  depth  anywhere  on  the  south  side  of  the  ridge  before 
-mentioned.  A  tough,  plastic,  blue  clay  distinguishes  the  line  of  the  break 
in  this  portion  of  its  course,  at  least,  and  where  the  line  crosses  Little 

299 


300         UESERVOIUS  FOR  lElilGATlON,  WATEUrOWER,  ETC. 


Hook  Creek  the  blue  clay  has  fornied  a  submerged  dam,  which  has  forced 
the  underflow  to  rise  near  the  surface  and  created  a  "  cienega  "  immediately 
above  it.  After  crossing  the  line  the  water  of  the  creek  drops  quickly  away 
into  the  deep  gravel  and  sand  of  the  wash.  The  same  effect  is  noticeable 
at  other  streams,  and  the  earthquake  crack  has  been  suggested  as  the 
probable  cause  of  the  very  distinct  rim  marking  the  lower  margin  of  the 
San  Bernardino  Valley  artesian  basin  and  confining  its  waters  within  well- 
defined  limits,  as  this  rim  is  nearly  on  a  prolongation  of  the  line  that  is 
traceable  on  the  north  side  of  the  mountains —the  break  having  possibly 
crossed  the  mountains  through  the  Cajon  Pass  on  the  line  of  Swartout 
Canyon. 

One  of  the  largest  depressions  on  the  earthquake  line  is  the  basin  near 
Alpine  or  Harold  station  ,  on  the  Southern  Pacific  Railroad,  which  has 
always  held  a  small  amount  of  water,  supplied  by  the  rainfall  over  the 
small  catchment  of  6  or  8  square  miles  above  it,  but  which  is  now  trans- 
formed into  a  reservoir  fed  by  a  canal,  8.6  miles  long,  from  Little  Rock 
Creek.  The  railway  passes  through  one  side  of  the  basin  and  crosses  the 
outer  rim  near  the  outlet-tunneL  A  low  levee  or  dike,  about  4000  feet 
long,  will  have  to  be  built  alongside  the  track  to  enable  the  reservoir  to 
be  filled  to  its  maximum  depth  of  34  feet,  for  which  it  has  been  planned. 
At  this  level  it  will  cover  263  acres  of  surface  and  impound  5500  acre-feet 
of  water.  The  basin  will  carry  15  feet  of  water  without  submerging  the 
track,  and  for  present  purposes  a  dike  lower  than  that  which  is  planned 
for  a  full  use  of  the  basin  has  been  built  to  permit  the  storage  of  21  feet 
depth  of  water.  A  corner  of  the  basin  is  shown  in  Fig.  135  as  it  appeared 
before  beginning  work.  The  view  is  taken  looking  east  across  the  railroad- 
,.  tracks  toward  the  mountain  source  of  supply. 

The  feeder-canal  from  Little  Rock  Creek  consists  of  2  miles  of  flume 
and  chute  and  6^  miles  of  earth  canal,  including  two  ponds  used  as  sand- 
settling  basins,  1600  and  1400  feet  long.  The  location  of  the  conduit, 
after  getting  out  of  the  canyon  of  the  creek,  is  directly  on  the  earthquake 
line  for  the  greater  part  of  the  way,  the  straightness  of  the  line  being 
noticeable  on  the  map,  Fig.  134.  The  canal  heads  at  an  elevation  of 
3130  feet  above  sea-level,  and  it  has  a  total  fall  to  the  surface  of  the  reser- 
voir of  317  feet,  of  which  the  canal  grade  required  but  70  feet.  The 
superfluous  fall  was  taken  up  by  a  series  of  inclines  or  chutes,  down 
which  the  water  flows  with  great  velocity.  They  are  seven  in  number  and 
have  a  total  length  of  4600  feet.- 

The  canal  has  a  maximum  capacity  of  250  to  300  second-feet.  Under 
normal  conditions  it  is  expected  that  the  reservoir  can  be  filled  twice  or 
more  each  season,  and  by  irrigating  freely  in  winter  and  early  spring  the 
duty  of  the  reservoir  and  canal  system  may  be  increased  to  accomplish  the 
irrigation  of  as  great  an  area  as  though  the  reservoir  were  of  double  the 


302 


RESERVOIRS  FOR  1RRI(',ATI0N.   WATER-POWER,  ETC. 


capjK'ily.  The  iraci  which  the  company  hopes  to  supply  from  this  source 
covers  about  10,000  acres,  a  })art  of  which  is  being  planted  in  olives. 

The  watershed  oi*  Little  Eock  Creek,  as  shown  by  the  best  maps  to  be 
had,  docs  not  exceed  61  square  miles,  but  as  it  heads  in  one  of  the  highest 
peaks  of  the  Sierra  Madre  and  drains  the  north  slopes  of  the  mountain, 
the  run-off  to  be  expected  from  it  may  ordinarily  reach  400  acre-feet  per 


Fig.  134.— Map  of  Little  Rock  Ckeek  Irrigation  District. 

square  mile.  The  normal  flow  of  the  stream,  which  reaches  a  minimum  of 
2  second-feet,  is  diverted  at  the  before-mentioned  earthquake  cienega  by 
a  ditch  supplying  the  Little  Rock  Irrigation  District,  the  outhnes  of  which 
are  shown  on  the  sketch-map  (Fig.  134).  Consequently  the  South  Ante- 
lope Valley  Company  must  depend  entirely  upon  the  surplus  flood-water 
after  the  district  is  supplied. 

Incidentally  it  will  be  of  interest  in  this  connection  to  mention  that 
a  careful  measurement  of  the  underflow  in  the  gravel  bed  of  the  stream 
overlying  the  blue  clay  of  the  earthquake  crack,  made  by  Mr.  J.  B. 
Lippincott  in  June,  1896,  resulted  in  the  conclusion  that  the  rate  of  flow 
of  the  percolating  water  passing  through  the  sand  and  gravel  of  the 


NATURAL  RESERVOIRS. 


305 


channel  was  2.16  feet  per  hour,  or  3.53  miles  per  annum,  which  is  ex- 
tremely slow,  but  much  greater  than  that  noted  at  the  Agua  Fria  River, 
Arizona  .(p.  210),  doubtless  because  of  the  greater  coarseness  of  the  gravel 
at  Little  Eock. 

The  outlet  to  the  Alpine  reservoir  (Figs.  135,  136)  is  made  by  a  tunnel 
750  feet  long,  in  which  a  36-inch  riveted  steel  pipe  is  laid  for  irrigation 
supply  alone,  and  a  10-inch  pipe  of  the  same  character  is  placed  above 
the  former  for  domestic  purposes  only,  both  being  surrounded  with  con- 
crete, filling  the  8-inch  space  concentric  with  the  pipes  to  the  walls  of  the 
tunnel.  The  pipes  extend  only  200  feet  from  the  interior  to  a  gate-shaft, 
and  thence  the  main  pipe  discharges  into  a  flume  placed  inside  the  tunnel- 
timbers.  This  flume  is  2  feet  deep,  3  feet  8  inches  wide,  and  delivers  the 
water  to  the  distributing-ditches  running  east  and  west  from  the  mouth 
of  the  tunnel  on  suitable  grade-lines.  A  wooden  platform  on  a  trestle 
built  over  the  inner  end  of  the  tunnel  serves  as  a  place  from  which  to 
operate  the  36-inch  gate-valve  at  the  head  of  the  pipe  and  three  10-inch 
valves  on  a  stand-pipe  at  different  levels  controlling  the  domestic  supply, 
which  is  taken  under  pressure  to  the  town  of  West  Palmdale.  The  works 
were  planned  and  built  by  Burt  Cole,  a  civil  engineer  residing  in  the  dis- 
trict.   The  cost  of  the  system  was  about  ;$100,005. 

Twin  Lakes  Reservoir,  Colorado.— One  of  the  reservoir-sites  surveyed 
by  the  government  in  1892  was  the  Twin  Lakes  site,  on  a  fork  of  the 
Arkansas  River  (Fig.  137).  These  lakes  cover  an  area,  at  normal  stage  of 
water,  of  about  1900  acres,  and  have  a  depth  of  more  than  80  feet.  They 
are  at  an  altitude  of  9194  feet,  and  receive  the  drainage  from  387  square 
miles  of  watershed,  including  within  this  area  some  of  the  highest  moun- 
tains of  Colorado.  The  annual  run-off  from  this  area  is  from  40,000  to 
100,000  acre-feet. 

The  plan  proposed  by  the  government  engineers  for  utilizing  these  two 
lakes  and  converting  them  into  one  large  reservoir  was  to  erect  an  earth 
dam,  with  a  maximum  height  of  73  feet,  across  the  valley  below  the  lakes, 
and  thus  increase  their  surface  area  to  3475  acres.  This  would  give  a 
reservoir  capacity  above  the  normal  lake  surface  of  103,500  acre-feet. 
To  fill  the  reservoir  it  was  designed  to  supplement  the  run-off  of  the 
streams  directly  tributary  by  diverting  water  from  the  main  Arkansas 
River,  by  a  canal  leaving  the  river  a  short  distance  below  Leadville. 

Some  years  after  this  survey  was  made  a  private  corporation,  called  the 
Twin  Lakes  Reservoir  Company,  was  organized  by  Buffalo  capitalists  to 
carry  out  the  work  on  a  modified  plan.  This  company  acquired  sufficient 
land  around  the  margins  of  the  lakes  to  control  them,  and  began  work 
in  the  summer  of  1898.  The  plan  adopted  by  them  contemplated  works 
that  would  enable  them  to  draw  off  the  lakes  to  16  feet  below  their  normal 
level,  and  in  addition  build  a  low  dam  that  would  store  9  feet  in  depth 


3()()         RESERVOIRS  FOR  IRRTGATWN,  WATER-POWER,  ETC. 


above  that  level —thus  commanding  a  total  dcj)tli  of  25  feet  and  a  total 
volume  of  48,000  acre-feet.  Of  this  volume,  two-thirds,  or  32,000  acre- 
feet,  is  below  the  normal  lake-level.  In  pursuance  of  this  plan  they  ex- 
cavated a  canal  at  one  side  of  the  outlet-stream,  2000  feet  long,  from 
the  edge  of  the  lower  lake  to  the  point  of  its  intersection  with  Lake  Creek. 
This  canal  is  40  feet  wide  on  bottom,  and  has  a  maximum  depth  of  37  feet. 
The  excavation  was  in  sand,  bowlders,  and  silt,  or  "  glacial  flour,''  and  was 
chiefly  made  with  a  steam-shovel.   At  the  point  where  the  excavation  was 


E/.&770 


Lon^/tud/na/  Sec.  of  €ut/et  Tan/jeJ'^^/^  Reseri/oir 


Sec 
Typicc!  Shute 


See 


Coi/ered  Box  -F/ume 


Sec. 
TunneA 

T/mderz/jg  '^Sec.Bench  F/ume 

Out/et\ 
Tu/7ne/\ 
T/mbering 


Pipes  in 
Outlet  Tunnel 

Fig.  136.— Details  of  Tunnel-outlet  of  the  Alpine  Reservoir. 

deepest,  some  200  feet  from  the  lake  margin,  they  prepared  to  erect  head- 
gates  of  iron,  on  a  heavy  base  of  concrete,  with  abutment-walls  of  cut 
stone  laid  in  cement  mortar.  The  structure  was  to  have  been  32  feet  in 
height.  The  gates  were  twelve  in  number,  each  2  feet  8^  inches  wide, 
5  feet  high,  made  of  ^-inch  boiler-plate,  and  carrying  iron  flashboards, 
loosely  resting  one  above  another,  on  top  of  the  gate,  and  reaching  up  to 
above  high-water  mark.  The  gates  were  to  slide  vertically  between  12-inch 
I  beams.  These  beams  were  to  be  embedded  in  the  concrete  floor.  The 
foundations  for  this  floor  were  made  by  driving  piles,  upon  which  the 
abutment-walls  and  center  pier  rest.    (Fig.  138.) 

The  concrete  base  of  the  gate  structure  was  planned  and  built  72  feet 
long,  with  a  width  of  69  feet  to  the  outer  lines  of  the  abutment-walls.  It 
was  made  5  feet  in  thickness,  with  double  grillage  of  T  rails,  encased  in 
the  concrete.  Three  lines  of  apron  or  curtain  walls  extended  down  5  feet 
below  the  bottom  of  the  concrete,  across  the  line  of  the  canal. 


"NtVEfisiry'onLUNOi; 


SOO         HESERVOIRS  FOR  IRRIGATION,  WA7ER-P0WER,  ETC. 


above  tluit  level —thus  coniiiiaiuliDg  a  total  depth  of  25  feet  and  a  total 
volume  of  48,000  acre-feet.  Of  this  volume,  two-thirds,  or  32,000  acre- 
feet,  is  below  the  normal  lake-level.  In  pursuance  of  this  plan  they  ex- 
cavated a  canal  at  one  side  of  the  outlet-stream,  2000  feet  long,  from 
the  edge  of  the  lower  lake  to  the  point  of  its  intersection  with  Lake  Creek. 
This  canal  is  40  feet  wide  on  bottom,  and  has  a  maximum  depth  of  37  feet. 
The  excavation  was  in  sand,  bowlders,  and  silt,  or  "  glacial  flour,"  and  was 
chiefly  made  with  a  steam-shovel.   At  the  point  where  the  excavation  was 


Lon^/tud/na/  Sec.  of  Outlet  Tun/jeA^iS/r)  Reseri/oir 


See 

Covered  Box  -F/ume 


Q 


Sec. 
Tunne/X 

^  T/mder/ng'^Sec.Bench F/ume 


Outlet 
Tu/y/je/ 
T/mdering 


Mm 


Trestle 
Bents 


Pipes  in 
Outlet  Tunnel 


Fig.  136.— Details  of  Tunnel-outlet  of  the  Alpine  Reservoiii. 

deepest,  some  200  feet  from  the  lake  margin,  they  prepared  to  erect  head- 
gates  of  iron,  on  a  heavy  base  of  concrete,  with  abutment-walls  of  cut 
stone  laid  in  cement  mortar.  The  structure  was  to  have  been  32  feet  in 
height.  The  gates  were  twelve  in  number,  each  2  feet  8-|  inches  wide, 
5  feet  high,  made  of  l-inch  boiler-plate,  and  carrying  iron  flashboards, 
loosely  resting  one  above  another,  on  top  of  the  gate,  and  reaching  up  to 
above  high-water  mark.  The  gates  were  to  slide  vertically  between  12-inch 
I  beams.  These  beams  were  to  be  embedded  in  the  concrete  floor.  The 
foundations  for  this  floor  were  made  by  driving  piles,  upon  which  the 
abutment-walls  and  center  pier  rest.    (Fig.  138.) 

The  concrete  base  of  the  gate  structure  was  planned  and  built  72  fget 
long,  with  a  width  of  69  feet  to  the  outer  lines  of  the  abutment-walls.  It 
was  made  5  feet  in  thickness,  with  double  grillage  of  T  rails,  encased  in 
the  concrete.  Three  lines  of  apron  or  curtain  walls  extended  down  5  feet 
below  the  bottom  of  the  concrete,  across  the  line  of  the  canal. 


Fig/  137. 

[To  face  page  307. 


NSAS  RIVER  BASIN 


muer  H.BodOsh.En^eer. 

fm  Capacity  103500  AcreFeeti 
B89 


NATURAL  RESEEVOIBS. 


307 


In  the  spring  of  1899  this  structure  was  partially  completed,  the  floor 
was  finished,  and  one  of  the  abutment-walls  was  built  12  feet  high,  when 
work  was  stopped  by  threats  of  injunction  made  by  officials  of  the  Denver 
and  Rio  Grande  and  the  Colorado  Midland  railways,  whose  tracks  through 
the  canyon  of  the  river  below  would  have  been  endangered  by  any  failure 
of  the  proposed  reservoir.  At  this  juncture  Mr.  0.  0.  McReynolds  was 
appointed  Chief  Engineer,  and  the  writer  was  employed  as  Consulting 
Engineer  to  prepare  plans  to  make  the  work  secure  and  allay  apprehen- 
sions of  its  safety.  The  modifications  which  were  made  in  the  plan  are 
shown  in  Fig.  137,  and  the  work  has  since  been  completed  in  compliance 
with  the  new  design.  The  changes  were  made  in  such  manner  as  to  adapt 
them  to  the  part  already  completed  and  to  utilize  materials  already  on  the 
ground.  These  were  the  following:  A  series  of  four  culverts  were  built 
on  top  of  the  completed  floor,  extending  from  the  line  of  gates  to  the 
lower  edge  of  the  concrete  platform,  a  distance  of  47  feet.  These  culverts 
are  each  7  feet  11  inches  wide  and  7  feet  high,  with  a  semicircular  arch 
over  them.  They  are  built  of  concrete,  the  thickness  of  the  arch  being 
2  feet.  On  top  of  these  culverts  a  masonry  dam  is  built  across  the  canal, 
reaching  to  a  height  of  30  feet  above  the  floor  of  the  structure.  This 
wall  is  of  sandstone  ashlar,  laid  in  large  blocks  with  Portland-cement 
mortar.  Its  base  width  is  15  feet,  top  4  feet;  down-stream  batter  5  :  12. 
Extending  well  into  the  banks  on  each  side,  in  line  with  the  dam,  is  a  con- 
crete wall,  2  feet  thick,  designed  to  cut  off  seepage  through  the  earth 
filling  on  the  sides  that  would  tend  to  pass  around  the  dam.  Against  the 
masonry  dam  on  the  lower  side  is  an  embankment  of  earth  over  the  top  of 
the  culverts,  forming  a  driveway  over  the  canal,  22  feet  wide  on  top. 
The  outer  slope  terminates  against  a  low  wall  forming  a  fagade  for  the 
culvert-portals.  The  slope  is  paved  with  stone.  For  50  feet  above 
and  75  feet  below  the  concrete  platform  the  canal  is  paved  with  con- 
crete on  the  bottom,  and  the  sides  protected  from  erosion  by  substantial 
walls  of  concrete  above  the  dry  rubble  below  the  headworks.  The  gates 
built  for  the  original  design  were  used,  but  the  hoisting-device  was  im- 
proved, and  a  substantial  gate-house  built  over  the  gates. 

Spillway. — A  space  is  left  between  the  gates  and  the  masonry  which 
will  admit  of  a  maximum  discharge  of  600  second-feet  over  the  top  of  the 
flashboards,  without  raising  the  gates.  Whenever  any  water  thus  passes 
over  the  top  of  the  flashboards  it  can  escape  freely  through  the  culverts 
and  down  the  canal.  This  provision  for  sudden  floods  in  the  possible 
absence  of  attendants  to  open  the  gates  is  considered  an  ample  spillway 
allowance.  The  culverts  have  a  combined  capacity  of  over  2000  second- 
feet. 

FisJiway. — To  provide  for  a  free  passage  of  migratory  fish  over  the 
dam,  in  compliance  with  the  State  law,  it  is  proposed  to  erect  a  fish-ladder 


308         RESERVOIRS  FOR  IRRIOATTON,  WATER-POWER,  ETC. 


NATUBAL  RESERVOIRS. 


309 


of  approved  design,  supplying  it  with  water  piped  from  a  neighboring 
stream.    The  lakes  abound  in  trout. 

The  entire  cost  of  the  improvements,  including  the  purchase  of  valuable 
villa  sites  on  the  lake  margins,  will  be  about  $200,000.  The  works  were 
finished  during  the  current  year  (1900). 

"  Glacial  Flour  J' — An  interesting  feature  of  these  improvements  is  the 
peculiar  character  of  the  material  through  which  the  canal  has  been 
excavated  and  upon  which  the  head-works  have  been  built.  The  lakes  are 
located  between  two  great  lateral  moraines,  hundreds  of  feet  in  height, 
while  the  barrier  across  the  valley,  forming  the  natural  dam  inclosing 
the  lower  lake,  is  a  terminal  moraine  deposit,  consisting  largely  of  rock 
dust,  or  almost  pure  silica  ground  to  an  impalpable  powder,  known  to 
geologists  as  "  glacial  flour."  This  material  is  so  fine  in  texture  as  to 
resist  percolation  through  any  considerable  mass  of  it,  and  hence  it  be- 
comes practically  impervious  as  an  embankment  of  ordinary  dimensions. 
It  is  neither  quicksand  nor  clay,  and  has  none  of  the  characteristics  of 
these  elements. 

The  natural  channel  through  which  the  lakes  overflow  into  the 
Arkansas  Eiver  will  be  closed  by  an  embankment  of  this  glacial  flour, 
well  riprapped  with  stone  on  both  sides. 

Larimer  and  Weld  Reservoir. — One  of  the  natural  basins,  located 
miles  north  of  Fort  Collins,  Colorado,  has  been  made  to  hold  an  important 
auxiliary  supply  to  the  Larimer  and  Weld  canal,  feeding  into  the  latter 
2  miles  below  the  head  of  the  canal.  When  filled  to  the  rim  it  holds  a 
maximum  depth  of  25  feet,  and  has  a  storage  capacity  of  7700  acre-feet 
at  that  level.  This  capacity  was  increased  in  1895  to  11,550  acre-feet  by 
constructing  a  low  levee  or  bank  about  2000  feet  long  at  the  lowest  part 
of  the  rim  of  the  basin.  This  added  5  feet  to  the  depth  of  water  in  the 
lake. 

The  cost  of  the  improvements  was  $21,796,  but  land  and  water  rights, 
attorneys  and  court  fees,  and  miscellaneous  expenses  swelled  the  entire 
cost  to  $64,782.  On  the  same  canal  system  are  two  other  natural  basins, 
utilized  as  reservoirs,  the  larger  of  which,  called  the  Windsor  reservoir,  is 
25  miles  below  the  head  of  the  canal.  It  carries  a  maximum  depth  of  28 
feet  of  water,  and  cost  $52,000,  of  which  $25,000  was  for  the  land  and 
attorneys'  fees.  To  increase  the  depth  to  40  feet,  an  embankment  is  to  be 
built  which  is  estimated  to  cost  $23,000  additional.  The  reservoir  will 
then  have  a  capacity  of  23,000  acre-feet. 

The  Larrimer  County  Canal  utilizes  six  of  these  basins  on  the  plains, 
as  storage-reservoirs,  which  have  a  combined  capacity  of  10,560  acre- 
feet. 

All  of  these  basins  above  described  derive  their  water-supply  from  the 
Cache  la  Poudre  Eiver. 


310         BESEBVO/liS  FOR  llUiJGATlON,  WATER-POWKR,  ETC. 


Marston  Lake. — One  oi'  the  largest  of  these  natural  basins,  situated  at 
an  elevation  to  command  the  city  oi*  Denver,  has  been  utilized  by  the 
Denver  Union  Water  Company  as  a  storage-reservoir  of  5,000,000,000 
gallons  capacity.  It  is  fed  by  a  canal  from  Bear  Creek,  and  is  provided 
with  two  outlet-tunnels  which  connect  with  the  main  conduits  leading  to 
the  city  of  Denver,  10  miles  distant. 

Loveland  Reservoir-site. — One  of  the  largest  of  the  natural-basin 
reservoirs  that  has  been  projected  for  use  in  Colorado  is  located  3  miles 
northeast  of  Loveland,  Colorado,  at  Boyd  Lakes.  These  are  two  basins 
adjacent,  each  containing  small  lakes,  on  the  high  ground  between  the 
Cache  la  Poudre  and  Big  Thompson  rivers.  The  basin  will  require  no 
dam,  and  when  filled  will  have  a  maximum  depth  of  44  feet,  and  a  surface 
area  of  1920  acres,  the  capacity  of  which  will  be  45,740  acre-feet. 

The  method  proposed  for  its  conversion  into  a  reservoir  is  to  make  an 
open  cut,  10  feet  wide  at  the  bottom,  on  a  grade  of  1.5  feet  per  mile.  At 
the  deepest  point  in  the  cut  a  masonry  wall  is  proposed  to  be  built  across 
the  cut,  with  six  3-foot,  cast-iron  pipes  passing  through  the  wall.  The 
reservoir  would  be  fed  by  two  canals  from  the  rivers  on  each  side  of  it. 
The  entire  cost  of  the  improvement  is  estimated  by  Capt.  H.  M.  Chitten- 
den *  at  $262,106.34,  or  $5.73  per  acre-foot  of  storage  capacity. 

The  Laramie  Natural  Reservoir-site,  Wyoming. — Capt.  Chittenden's 
able  report  f  on  reservoir-sites  in  Wyoming  and  Colorado  describes  a 
natural  basin  that  could  be  made  available  for  storing  the  surplus  water 
of  the  Laramie  and  Little  Laramie  rivers,  which  is  one  of  colossal  magni- 
tude. Its  maximum  depth  is  170  feet,  covering  an  area  of  13,651  acres, 
and  having  a  capacity  of  937,038  acre-feet.  This  is  greatly  in  excess  of 
the  supply  available  from  the  two  streams  mentioned,  which  is  estimated 
at  70,000  acre-feet  annually,  although  this  couM  be  increased  by  gathering 
the  supply  from  more  distant  sources. 

When  filled  to  the  100-foot  level,  the  annual  loss  by  evaporation  would 
be  24,000  acre-feet,  leaving  a  supply  of  46,000  acre-feet  for  irrigation. 
The  estimated  cost  of  the  canals,  reservoir-outlets,  rights  of  way,  etc., 
for  utilizing  the  basin  on  the  basis  of  storing  only  the  waters  of  the  two 
Laramie  rivers,  was  $416,254,  or  $9.05  per  acre-foot  of  average  supply. 

Lake  De  Smet  Reservoir-site,  Wyoming. — Among  the  reservoir-sites 
examined  and  reported  upon  by  Capt.  Chittenden,  in  the  report  quoted 
above,  was  a  natural  depression  without  outlet,  called  Lake  De  Smet. 
This  basin  is  3  miles  long,  1  mile  wide,  and  covers  an  area  of  1965  acres. 
The  improvement  of  this  basin  which  he  recommended  was  to  construct 

*  Report  of  Capt.  Hiram  M.  Chittenden,  Corps  of  Engineers,  U.  S.  A.,  upon  examina- 
tion of  Reservoir-sites  in  Wyoming  and  Colorado,  under  the  provisions  of  Act  of  Con- 
gress of  June  3,  1896.    House  Document  No.  141,  55th  Congress,  2d  Session. 

t  lUd. 


NATURAL  RESERVOIRS. 


311 


a  feeder-canal,  3^  miles  long,  with  a  capacity  of  727  second-feet,  and  con- 
struct two  outlets,  one  at  each  end  of  the  basin,  discharging  into  Box 
Elder  Creek  on  one  side  and  into  Piney  Creek  on  the  other,  each  to  have 
a  capacity  of  425  second-feet.  This  would  convert  the  basin  into  a  reser- 
voir by  the  addition  of  30  feet  in  depth,  bringing  the  level  of  the  lake  up 
to  the  rim  of  the  basin,  increasing  its  surface  area  to  2400  acres,  and 
affording  an  available  storage  of  67,627  acre-feet  of  water.  The  entire  cost 
of  the  improvement  was  estimated'  at  $113,360,  or  $1.67  per  acre-foot  of 
storage  capacity. 

Such  natural  basins  as  those  described  in  the  foregoing  pages,  which 
can  be  filled  by  controllable  canals,  present  advantages  as  storage-reser- 
voirs which  are  certainly  ideal.  The  great  thickness  of  the  natural  ridges 
which  surround  them  renders  them  absolutely  safe  against  bursting,  pro- 
vided their  outlets  are  properly  designed  and  well  constructed;  they  are 
generally  quite  free  from  loss  by  percolation,  and  the  volume  of  silt  de- 
posited in  them  is  in  direct  ratio  to  their  capacity,  as  no  more  silt-laden 
water  need  be  put  into  them  than  is  drawn  out  of  them  for  use,  in  addition 
to  evaporation,  whereas  a  reservoir  located  in  the  channel  of  a  river  may 
often  have  to  receive  the  silt  from  a  volume  of  water  many  times  the 
reservoir  capacity.  The  only  disadvantage  they  possess  is  that  the  surface 
area  exposed  may  be  greater  per  unit  of  volume  stored  than  in  deep  reser- 
voirs formed  by  high  dams,  and  consequently  the  ratio  of  loss  by  evapora- 
tion may  be  somewhat  greater. 

This  disadvantage  is,  however,  amply  offset  by  the  many  superior 
features  they  possess  when  compared  with  the  average  stream-bed  reser- 
voir. 

Natural  Reservoirs  of  the  Arkansas  Valley,  Colo. — The  most  extensive 
enterprise  for  the  storage  of  flood  waters  for  irrigation  in  natural-basin 
reservoirs  yet  undertaken  in  the  West  was  recently  completed  by  The  Great 
Plains  Water  Company  in  the  Arkansas  Valley  in  Eastern  Colorado,  and 
the  reservoirs  were  partially  filled  and  used  for  the  first  time  during  the 
irrigation  season  of  1900.  The  reservoirs  are  five  in  number,  lying  in  a 
group  closely  adjacent  to  each  other,  and  have  the  following  capacities: 


*  Name  of  Reservoir. 


Nee  Sopah.. 
Nee  Gronda, 
Nee  Noshe. . 
Nee  Skah. . . 
King  


Area. 

Total 
Capacity. 

Volume  below 
Outlet  Level 

and 
Unavailable. 

Volume 
Available 
for  Use. 

Acres. 

Acre-feet. 

Acre-feet. 

Acre-feet. 

8,600 
3,490 
3.770 
1,930 
1,381 

34,372 
97,069 
82,121 
32,9«5 
18.279 

10.908 
39,860 
21,485 
9,939 

23,464 
57,209 
60,636 
28,046 
18,279 

14,121 

264,826 

82,192 

182,635 

followinfir  interpretations:  Nee  Sopah,  Black-water;  Nee  Gronda,  Big- water  •  Nee 
Noshe.  Standing-water  ;  Nee  Skah,  White- water. 


312         RESEliVOIES  FOli  lERlOATION,  WATER  POWER,  ETC. 


The  reservoirs  are  located  12  to  18  miles  north  of  the  town  of  Lamar, 
and  are  fed  by  a  canal  from  the  Arkansas  River,  which  heads  near  La  Junta, 
Colo,  and  has  a  maximum  capacity  of  209G  second-feet.  The  company 
has  built  various  other  canals,  as  shown  by  the  following  table: 

Length  in  Capacity  in 

Name  of  Canal.  Miles.  Sec  ft. 

Fort  Lyon   113.00  S096 

Kicking  Bird   36.50  1000 

Satanta    12-50  300 

Comanche   16-78  400 

Pawnee   6.34  200 

Amity    110-00  Zl  ' 

Buffalo   16-10 

The  company  has  invested  about  $2,250,000  in  its  irrigation  works  and 
lands,  the  area  of  its  holdings  being  about  100,000  acres.  The  manager  of 
the  company  is  Mr.  W.  H.  Wiley,  of  New  York,  now  residing  at  Holly, 

The  three  reservoirs  described  in  the  foregoing  table  are  so  connected 
that  they  can  be  drawn  upon  by  one  outlet.  This  has  been  formed  by  a 
deep  cut  through  the  rim  of  the  basin,  in  which  the  gates  are  placed  m 
substantial  headworks  of  cut-stone  masonry.    The  outlet  to  Nee  Skah  is 

of  a  similar  plan.  The  King  reservoir  as  yet  has  ^°  °^tl.«^\P/7'^f.*:'^^tl 
Natural  Gravel-bed  Storage-reservoirs.-It  may  be  said  that  all  the  sou 
of  the  earth  is  a  storage-reservoir,  which  receives  a  large  P/oportion  o  the 
precipitation  from  the  clouds  and  gives  it  off  slowly  to  feed  the  natural 
springs  by  which  the  normal  flow  of  the  streams  is  maintained.  These 
natural  reservoirs  are  increased  in  capacity  and  useful  Action  by  a 
maintenance  of  the  forests,  which  shade  the  ground,  lessen  the  force  o 
the  winds,  increase  the  humidity  of  the  air,  diminish  evaporation  and  knit 
the  soil  together  with  a  network  of  roots  and  so  enable  it  to  resist  erosion. 

In  many  parts  of  the  country  the  storm-waters  from  the  mountains 
flow  over  great  beds  of  coarse  gravel,  extending  from  the  foot-hills  out  into 
the  valleys,  for  many  miles.  These  gravel  beds  constitute  natural  storage- 
reservoirs  of  enormous  capacity,  and  if,  at  some  lower  point,  a  contraction 
occurs  in  the  stream-channel,  or  some  natural  barrier  intercepts  the  flow, 
the  water  is  again  forced  to  appear  on  the  surface  and  feeds  the  stream  by 
a  constant  outpouring  from  the  gravel  reservoir,  long  after  the  feeders  of 
the  reservoir  have  gone  dry.  ,      ,  , 

In  southern  California  there  are  a  number  of  such  natural  reservoirs 
one  of  the  most  notable  of  which  is  in  the  San  Fernando  Valley  north  of 
Los  Angeles,  and  supplies,  by  its  natural  overflow,  the  Los  Angeles  River. 
The  San  Fernando  Valley  has  an  area  of  182  square  miles,  about  one- 


NATURAL  RESERVOIRS.  313 

fourth  of  which  is  a  deep  bed  of  coarse  gravel,  constituting  a  natural 
storage-reservoir.  The  valley  is  surrounded  by  mountains,  of  which  about 
300  square  miles  in  the  area  drains  into  the  valley.  At  its  outlet  the  valley 
narrows  down  to  a  width  of  about  2  miles,  and  at  this  first  contraction 
the  Los  Angeles  Eiver  begins  to  appear,  growing  by  rapid  accretions  in  the 
space  of  a  mile  or  more,  at  the  rate  of  10  to  25  miner's  inches  per  100  feet 
of  channel.  All  the  streams  flowing  into  the  valley  are  intermittent,  and 
for  months  at  a  time  have  practically  no  surface-flow.  The  overflow  of  the 
gravel  reservoir,  however,  is  practically  constant  through  all  seasons,  wet 
and  dry,  mamtaining  a  discharge  of  from  70  to  90  second-feet.  Even  after 
three  seasons  of  drouth  the  river  at  the  present  writing  shows  a  diminution 
of  but  about  15%  from  the  normal. 

The  Upper  San  Gabriel  Valley,  some  15  miles  east  of  Los  Angeles, 
constitutes  another  natural  reservoir,  of  somewhat  greater  discharge  "than 
that  of  the  Los  Angeles  Eiver.  The  passage  of  the  stream  through  the 
coast  range  of  hills  is  but  one  mile  in  width,  and  contracts  the  basin 
sufficiently  to  cause  the  reservoir  to  overflow  at  the  surface,  producing 
a  never-failing  water-supply  for  irrigation  in  the  valley  below.  Near  the 
outlet  of  the  upper  valley  a  number  of  artesian  wells  have  been  bored 
which  pierce  strata  of  impervious  clay  and  add  considerably  to  the  natural 
output  of  the  reservoir. 

The  San  Bernardino  Valley  is  another  interesting  example  of  nature's 
storage-reservoirs,  whose  overflow  at  the  narrows  below  yields  a  large  and 
unfailing  supply  to  the  adjacent  irrigated  districts.  This  valley  also  pro- 
duces a  large  artesian  flow  to  augment  the  supply  which  naturally  seeks 
outlet  to  the  surface,  as  the  overflow  of  the  gravel  reservoir. 

Only  second  in  importance  to  these  natural  reservoirs  which  retain 
water  and  let  it  out  to  the  surface  at  a  uniform  rate,  where  it  may  be 
diverted  by  gravity  to  the  lands,  are  the  great  artesian  basins  fed  by  under- 
ground streams,  which  require  to  be  tapped  by  the  boring  of  wells,  and 
the  more  numerous  and  widespread  subterranean  basins  from  which  water 
in  wells  may  be  pumped  in  practically  immeasurable  quantities. 


CHAPTER  VI. 


PROJECTED  RESERVOIRS. 

If  all  the  reservoirs  which  have  been  surveyed  and  projected  in  arid 
America  within  the  past  ten  years  were  to  be  constructed,  the  water- 
supply  which  they  would  conserve  for  irrigation  would  doubtless  far  ex- 
ceed in  volume  all  the  water  which  has  ever  been  made  use  of  from  the 
natural  streams,  or  from  the  reservoirs  already  built,  while  there  are  still 
vast  numbers  unexplored  which  may  be  developed  in  the  future. 

In  1890,  '91,  and  '92  a  comprehensive  series  of  reservoir  locations  were 
made  by  the  U.  S.  Geological  Survey,  and  by  Act  of  Congress  the  lands 
covered  by  the  sites  selected  were  segregated  and  withdrawn  from  public 
entry.  The  detail  of  this  work  is  found  in  the  11th,  12th,  and  13th 
Annual  Eeports  of  the  U.  S.  Geological  Survey. 

In  the  appendix  will  be  found  tables  giving  the  data  of  these  various 
reservoir-surveys,  the  height  of  dams  required,  the  area  of  reservoirs  and 
their  storage  capacity.  The  work  was  distributed  over  the  following  States 
and  Territories,  viz.: 

California  .  . 
Nevada  .... 
Colorado  .  .  . 
Montana  .  .  . 
N'ew  Mexico 

Utah  

Wyoming  . .  , 
Idaho   

Total  204 

The  most  capacious  reservoir-site  discovered  by  the  survey  at  this 
time,  and  doubtless  the  largest  in  the  United  States,  was  the  Swan  Lake 
reservoir,  on  Snake  River,  Idaho,  covering  an  area  of  over  32  square  miles, 
and  capable  of  impounding  1,500,000  acre-feet,  with  a  dam  125  feet  in 
height.    The  cost  of  the  dam  was  estimated  at  $500,000.    This  consider- 

314 


45  reservoir-sites. 


2 

C( 

55- 

(( 

48 

(C 

39 

(C 

13 

ec 

1 

a 

1 

PROJECTED  RESERVOIRS. 


315 


ably  surpasses  the  proposed  Swift  River  reservoir  in  Massachusetts,  whose 
capacity  is  given  at  1,245,000  acre-feet,  or  406  billions  of  gallons. 

Projected  Reservoirs  in  Wyoming. — Reference  has  been  made  in  a 
previous  chapter  to  the  able  report  of  Capt.  H.  M.  Chittenden,  U.S.A., 
to  the  Secretary  of  War,  on  reservoir-sites  in  Wyoming  and  Colorado.  The 
examination  of  this  matter  was  authorized  by  the  River  and  Harbor  Act 
of  June  3,  1896,  providing  for  "  the  examination  of  sites,  and  report  upon 
the  practicability  and  desirability  of  constructing  reservoirs  and  other 
hydraulic  works  necessary  for  the  storage  and  utilization  of  water,  to 
prevent  floods  and  overflows,  erosion  of  river-banks,  and  breaks  of  levees, 
and  to  reenforce  the  flow  of  streams  during  drought  and  low-water  seasons, 
at  least  one  site  each  in  the  States  of  Wyoming  and  Colorado. 

A  number  of  the  views  which  appear  in  this  book  have  been  kindly 
loaned  by  the  public  printer,  having  first  been  used  to  illustrate  Capt. 
Chittenden's  report,  for  which  the  writer  makes  due  acknowledgment. 

Five  reservoir  systems  were  examined  under  the  provisions  of  the 
Act  of  June  3,  1896,— three  in  Wyoming,  two  in  Colorado.  The  Wyoming 
reservoirs  reported  on  were  the  Laramie  site,  the  Sweetwater  site,  and  the 
Piney  Creek  system,  comprising  three  reservoir-sites,  viz.,  the  Cloud  Peak, 
the  Piney,  and  the  Lake  De  Smet  sites.  The  sites  examined  in  Colorado 
were  the  Loveland  site,  already  described  in  a  previous  chapter,  and  the 
South  Platte  site,  50  miles  above  Denver.  At  the  latter  site  the  Denver 
Union  Water  Company  is  constructing  a  high  dam,  which  is  described  in 
the  chapter  on  Rock-fill  Dams. 

The  Laramie  and  Lake  De  Smet  sites  have  already  been  referred  to  in 
a  previous  chapter,  in  the  class  of  natural  basins. 

The  Sweetwater  Site  is  located  on  the  Sweetwater  River,  at  a  point 
known  as  the  DeviPs  Gate,  about  65  miles  north  of  the  town  of  Rawlins, 
Wyo.  The  river  here  cuts  through  a  granite  ridge  with  a  remarkably  nar- 
row gorge,  and  only  about  35  feet  wide  at  the  water-surface,  330  feet  deep, 
and  400  feet  wide  on  top.  The  top  length  of  the  dam  at  the  100-foot  level 
will  be  but  150  feet.  Here  it  is  proposed  to  build  a  masonry  dam  about  100 
feet  high,  which  would  form  a  reservoir  13  miles  long,  covering  an  area  of 
10,578  acres,  and  having  a  storage  capacity  of  326,965  acre-feet.  The  cost 
of  the  work  is  estimated  at  $276,484.80  or  85  cents  per  acre-foot  of  ca- 
pacity. The  available  supply  for  storage  is  stated  at  about  100,000  acre- 
feet  annually. 

The  profile  of  the  dam  proposed  is  of  heavy  dimensions,  the  base  width 
being  94  feet  and  the  thickness  at  crest  25  feet,  yet  with  these  dimensions 
the  entire  cubic  contents  of  the  dam  are  but  21,534  cubic  yards.  The 
proposed  outlet  is  by  a  tunnel  1000  feet  long  in  the  solid  rock  around  the 
l)ase  of  the  dam.  The  estimate  includes  an  item  of  $75,000  as  the  value 
of  the  land  flooded  by  the  reservoir. 


CHAPTER  VI. 


PROJECTED  RESERVOIRS. 

If  all  the  reservoirs  which  have  been  surveyed  and  projected  in  arid 
America  within  the  past  ten  years  were  to  be  constructed,  the  water- 
supply  which  they  would  conserve  for  irrigation  would  doubtless  far  ex- 
ceed in  volume  all  the  water  which  has  ever  been  made  use  of  from  the 
natural  streams,  or  from  the  reservoirs  already  built,  while  there  are  still 
vast  numbers  unexplored  which  may  be  developed  in  the  future. 

In  1890,  '91,  and  '92  a  comprehensive  series  of  reservoir  locations  were 
made  by  the  F.  S.  Geological  Survey,  and  by  Act  of  Congress  the  lands 
covered  by  the  sites  selected  were  segregated  and  withdrawn  from  public 
entry.  The  detail  of  this  work  is  found  in  the  11th,  12th,  and  13th 
Annual  Eeports  of  the  IT.  S.  Geological  Survey. 

In  the  appendix  will  be  found  tables  giving  the  data  of  these  various 
reservoir-surveys,  the  height  of  dams  required,  the  area  of  reservoirs  and 
their  storage  capacity.  The  work  was  distributed  over  the  following  States 
and  Territories,  viz.: 

California  .  . 
Nevada  .... 
Colorado  .  .  . 
Montana  .  .  . 
New  Mexico 

Utah  

Wyoming  . .  . 
Idaho   

Total  204 

The  most  capacious  reservoir-site  discovered  by  the  survey  at  this 
time,  and  doubtless  the  largest  in  the  United  States,  was  the  Swan  Lake 
reservoir,  on  Snake  River,  Idaho,  covering  an  area  of  over  32  square  miles, 
and  capable  of  impounding  1,500,000  acre-feet,  with  a  dam  125  feet  in 
height.    The  cost  of  the  dam  was  estimated  at  $500,000.    This  consider- 

314 


45  reservoir-sites. 


2 

cc 

55- 

(( 

48 

<i 

39 

a 

13 

cc 

1 

cc 

1 

cc 

PROJECTED  RESEBVOIBS. 


315 


ably  surpasses  the  proposed  Swift  River  reservoir  in  Massachusetts,  whose 
capacity  is  given  at  1,245,000  acre-feet,  or  406  billions  of  gallons. 

Projected  Eeservoirs  in  Wyoming. — Reference  has  been  made  in  a 
previous  chapter  to  the  able  report  of  Capt.  H.  M.  Chittenden,  U.S.A., 
to  the  Secretary  of  War,  on  reservoir-sites  in  Wyoming  and  Colorado.  The 
examination  of  this  matter  was  authorized  by  the  River  and  Harbor  Act 
of  June  3,  1896,  providing  for  "  the  examination  of  sites,  and  report  upon 
the  practicability  and  desirability  of  constructing  reservoirs  and  other 
hydraulic  works  necessary  for  the  storage  and  utilization  of  water,  to 
prevent  floods  and  overflows,  erosion  of  river-banks,  and  breaks  of  levees, 
and  to  reenforce  the  flow  of  streams  during  drought  and  low-water  seasons, 
at  least  one  site  each  in  the  States  of  Wyoming  and  Colorado. 

A  number  of  the  views  which  appear  in  this  book  have  been  kindly 
loaned  by  the  public  printer,  having  first  been  used  to  illustrate  Capt. 
Chittenden's  report,  for  which  the  writer  makes  due  acknowledgment. 

Five  reservoir  systems  were  examined  under  the  provisions  of  the 
Act  of  June  3,  1896,— three  in  Wyoming,  two  in  Colorado.  The  Wyoming 
reservoirs  reported  on  were  the  Laramie  site,  the  Sweetwater  site,  and  the 
Piney  Creek  system,  comprising  three  reservoir-sites,  viz.,  the  Cloud  Peak, 
the  Piney,  and  the  Lake  De  Smet  sites.  The  sites  examined  in  Colorado 
were  the  Loveland  site,  already  described  in  a  previous  chapter,  and  the 
South  Platte  site,  50  miles  above  Denver.  At  the  latter  site  the  Denver 
Union  Water  Company  is  constructing  a  high  dam,  which  is  described  in 
the  chapter  on  Rock-fill  Dams. 

The  Laramie  and  Lake  De  Smet  sites  have  already  been  referred  to  in 
a  previous  chapter,  in  the  class  of  natural  basins. 

The  Sweetwater  Site  is  located  on  the  Sweetwater  River,  at  a  point 
known  as  the  Devil's  Gate,  about  65  miles  north  of  the  town  of  Rawlins, 
Wyo.  The  river  here  cuts  through  a  granite  ridge  with  a  remarkably  nar- 
row gorge,  and  only  about  35  feet  wide  at  the  water-surface,  330  feet  deep, 
and  400  feet  wide  on  top.  The  top  length  of  the  dam  at  the  100-foot  level 
will  be  but  150  feet.  Here  it  is  proposed  to  build  a  masonry  dam  about  100 
feet  high,  which  would  form  a  reservoir  13  miles  long,  covering  an  area  of 
10,578  acres,  and  having  a  storage  capacity  of  326,965  acre-feet.  The  cost 
of  the  work  is  estimated  at  $276,484.80  or  85  cents  per  acre-foot  of  ca- 
pacity. The  available  supply  for  storage  is  stated  at  about  100,000  acre- 
feet  annually. 

The  profile  of  the  dam  proposed  is  of  heavy  dimensions,  the  base  width 
being  94  feet  and  the  thickness  at  crest  25  feet,  yet  with  these  dimensions 
the  entire  cubic  contents  of  the  dam  are  but  21,534  cubic  yards.  The 
proposed  outlet  is  by  a  tunnel  1000  feet  long  in  the  solid  rock  around  the 
l)ase  of  the  dam.  The  estimate  includes  an  item  of  $75,000  as  the  value 
of  the  land  flooded  by  the  reservoir. 


316        RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 

Capt.  Chittenden  says  of  the  dam-site:  "  It  stands  almost  without  ex- 
ception as  the  most  favorable  site  for  a  masonry  dam  in  the  world." 

The  accompanying  photograph,  Fig.  139,  corroborates  this  statement. 
A  gap  in  the  ridge  at  one  side  of  the  dam  limits  the  height  to  100  feet,  and 
aifords  a  natural  spillway  of  any  desired  capacity. 

The  Cloud  Peak  Site  is  a  natural  lake,  about  1^  miles  long  and  I  mile 
wide,  covering  173  acres.  Its  elevation  is  nearly  10,000  feet  above  sea-level, 
and  it  is  surrounded  by  high  mountains  densely  clothed  with  forests.  The 
dam  proposed  for  this  site  is  the  combination  earth  and  rock-fill  of  the 
Pecos  Valley  type.  The  rock-fill  is  planned  with  side  slopes  of  1 :  1,  and 
a  top  width  of  5  feet.  Against  this  is  to  be  built  an  embankment  of 
puddled  earth,  with  a  crest  width  of  20  feet,  and  inner  slope  of  3  :  1.  The 
total  height  is  34  feet,  top  length  820  feet.  A  wasteway,  100  feet  wide, 
5  feet  deep,  is  planned.  The. high-water  mark  will  be  4  feet  below  the  crest 
of  the  dam.  By  means  of  a  sluiceway,  cut  10  feet  deeper  than  the  base 
of  the  dam,  it  is  proposed  to  draw  down  the  lake-level  10  feet,  giving  a 
total  available  capacity  of  6800  acre-feet.  The  drainage-area  is  30  square 
miles  in  extent,  from  which  the  run-off  will  fill  the  reservoir  every  year. 
The  estimated  cost  of  the  work  was  $31,048,  or  $4.56  per  acre-foot  of 
storage  capacity. 

The  Piney  Site  is  located  6  miles  below  the  Cloud  Peak  site,  at  an 
altidude  of  8800  feet.  It  requires  a  dam  54  feet  high  to  store  11,020 
acre-feet,  covering  a  surface  area  of  328  acres.  The  dam  proposed  is  about 
1000  feet  long,  and  is  planned  to  be  of  the  same  type  as  the  Cloud  Peak 
dam.  Its  cost  is  estimated  at  $70,226.25,  or  $6.37  per  acre-foot.  The 
total  drainage-area  above  this  site  is  65  square  miles. 

Capt.  Chittenden  has  given  in  his  report  the  ablest  and  most  convincing 
arguments  in  favor  of  the  construction  of  storage-reservoirs  in  the  arid 
West  by  the  IT.  S.  Government  that  have  yet  been  advanced  by  the  most 
ardent  advocates  of  that  policy.   He  says: 

"  Of  the  very  great  importance  of  irrigation,  not  only  to  the  West  but 
to  the  country  at  large,  there  would  seem  to  be  no  room  for  doubt.  To  one 
who  has  seen  the  changes  wrought  in  the  once  desert  regions  of  California, 
Arizona,  Utah,  Wyoming,  and  Colorado,  in  what  used  to  be  as  forbidding 
regions  as  any  still  remaining  in  that  country,  there  can  be  no  doubt  that 
the  destiny  of  the  arid  section  of  America  is  more  dependent  upon  the 
waters  that  flow  from  its  mountains  than  upon  the  minerals  that  lie  con- 
cealed within  them.  Already  in  the  greatest  mineral-producing  States  of 
the  West,  California  and  Colorado,  irrigated  agriculture  yields  a  greater 
wealth  of  product  than  the  mines.  .  .  .  Already  in  many  sections  the 
natural  flow  has  been  used  as  far  as  it  is  practicable  to  do  so.  .  .  .  Here, 
then,  is  a  definite  reason  of  the  highest  validity  for  the  construction  of 
reservoirs.  ...  The  inevitable  tendency  of  Western  development  is  there- 


Fig.  139.— The  "  Devil's  Gate,"  Sweetwater  Riyer,  Wyoming. 


317 


PROJECTED  BE8ERV0IRS. 


319 


fore  to  store  the  waters  of  the  streams,  and  the  limit  of  development  in 
this  direction  seems  certainly  to  be  nothing  less  than  the  final  utilization  of 
all  their  flow.  As  reservoirs  are  indispensable  aids  to  this  end,  it  will  be 
seen  that  their  construction  as  an  element  of  growth  of  the  Western  coun- 
try is  not  merely  ^  desirable  ' — it  is  absolutely  necessary.  What  is  the 
proper  agency  to  do  the  work?  " 

After  discussing  the  financial,  legal,  commercial,  and  physical  difficul- 
ties in  the  way  of  these  works  being  carried  out  by  private  individuals  or 
corporations  on  any  adequate  scale,  he  says: 

"  The  matter  of  private  or  corporate  construction  of  these  storage- 
works  is  therefore  seen  to  be  one  of  very  doubtful  practicability  from  a 
financial  point  of  view  alone,  while  in  neither  case  is  it  likely  that  reser- 
voir-sites would  be  developed  to  their  full  capacity,  as  they  should  be,  but 
only  to  the  extent  that  would  be  most  advantageous  to  the  investment 
itself.  ...  It  is  becoming  more  and  more  apparent  in  the  course  of  irriga- 
tion development  in  the  West  that  the  waters  of  the  streams  should  not  be 
made  the  subject  of  private  property,  but  they  should  inhere  in  the  land  to 
which  they  are  applied,  and  that  purchase  or  sale  of  water  as  a  commodity 
should  not  be  allowed.  Although  in  most  States  the  contrary  doctrine  has 
hitherto  prevailed,  the  disposition  of  the  courts  at  present  and  the  views 
of  practical  irrigators  seem  to  incline  more  and  mor^  to  the  doctrine  of 
the  public  character  of  all  streams.  .  .  .  It  is  clear  that  this  principle  can 
best  be  promoted,  so  far  as  stored  waters  are  concerned,  by  having  the 
storage-works  public  property.  A  proper  development  of  a  storage  system 
for  the  waters  of  Western  streams,  it  is  thus  seen,  cannot  be  expected 
through  private  agencies.  It  must  be  accomplished  through  some  form  of 
public  control." 

The  writer  then  shows  that  the  irrigation  district  system  of  public  con- 
trol, though  theoretically  advantageous,  has  practically  failed,  and  though 
the  system  may  be  improved,  it  could  not  be  sufficiently  comprehensive  to 
produce  best  results.  The  question  is  thus  resolved  to  State  and  national 
agencies  as  the  only  ones  qualified  to  deal  with  or  create  a  comprehensive 
reservoir  system.  He  concludes  that  "  the  work  is  distinctly  interstate  in 
character,  and  is  therefore  less  properly  a  State  than  a  national  enter- 
prise. Already  the  interstate  character  of  some  of  these  streams  is  giving 
rise  to  troublesome  questions,  which  only  Federal  authority  can  answer. 
In  the  case  of  reservoirs  it  not  infrequently  happens  that  some  of  the  very 
best  sites  are  to  be  found  close  to  State  lines,  where  the  waters  so  stored 
will  flow  immediately  into  neighboring  States.  In  these  extreme  cases  the 
States  where  they  are  located  could  not,  of  course,  be  expected  to  construct 
reservoirs,  and  the  States  to  be  benefited  would  not  be  likely  to  go  outside 
their  own  borders  to  do  so.  The  function  clearly  pertains  to  that  sov- 
ereignty which  covers  all  the  country  and  embraces  the  streams  from  their 


320        RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


sources  to  the  sea.  It  alone  can  store  these  waters  and  be  sure  that  it  is 
reaping  the  full  benelit. 

Another  reason  why  the  government  should  have  an  interest  in  this 
work  is  that  it  is  the  largest  landowner  in  the  arid  West.  In  Wyoming 
over  90  per  cent  of  the  soil  belongs  to  the  government,  and  its  holdings 
throughout  the  West  include  millions  of  acres  which  can  be  reclaimed  from 
their  present  desert  condition  and  made  productive  lands.  In  this  respect 
government  assistance  in  providing  water  for  irrigation  is  a  simple  busi- 
ness proposition  for  the  enhancement  of  its  own  property." 

In  summarizing  the  arguments  of  which  but  brief  extracts  have  been 
given  in  the  foregoing,  Capt.  Chittenden  draws  conclusions  from  which 
the  following  extracts  are  taken: 

"  Eeservoir  construction  in  the  arid  regions  of  the  West  is  an  indis- 
pensable condition  to  the  highest  development  of  that  section.  It  can  be 
properly  carried  out  only  through  public  agencies.  Private  enterprise  can 
never  accomplish  the  work  successfully;  as  between  State  and  nation,  it 
falls  more  properly  under  the  domain  of  the  latter. 

"  Eeservoir  construction  by  the  General  Government  need  not  in  any 
way  involve  government  control  of  irrigation-works.  These  should  be 
left  in  the  hands  of  the  States  and  private  individuals  under  State  laws. 

"  The  total  extent  of  a  reservoir  system  in  the  arid  regions  which  shall 
render  available  the  entire  flow  of  the  streams  will  not  exceed  1,161,600,- 
000,000  cubic  feet.  If  the  construction  of  such  a  system  were  to  consume 
a  century  in  time,  it  would  represent  an  annual  storage  of  266,300  acre- 
feet.  At  $5.73  per  acre-foot  this  would  cost  $1,430,031  per  annum.  This 
amount  distributed  among  the  seventeen  States  and  Territories  of  the 
arid  section  gives  an  average  annual  expenditure  in  each  of  $81,119.  The 
annual  value  of  the  stored  water  would  return  the  original  cost  and  main- 
tenance in  an  average  period  of  three  years." 

The  latter  statement  is  based  on  the  estimate  that  the  future  average 
annual  value  of  stored  water  for  irrigation  alone  throughout  the  arid  West 
is  not  less  than  $2  per  acre-foot,  which  is  certainly  conservative. 

Government  Reservoir  Surveys  in  Arizona. — The  waters  of  the  Gila 
Eiver  in  Arizona  have  been  used  for  irrigation  by  the  Pima  and  Maricopa 
Indians  from  time  immemorial,  on  the  lands  now  included  within  the 
limits  of  the  Gila  Eiver  Eeservation.  They  are  peaceable,  pastoral  tribes 
of  Indians,  accustomed  to  derive  their  livelihood  from  the  cultivation  of 
the  soil.  Within  the  past  decade,  however,  the  settlement  of  the  upper 
valleys  of  the.  Gila  by  white  farmers  has  been  followed  by  such  a  complete 
diversion  of  the  summer  flow  of  the  stream  on  the  irrigated  fields  above 
that  the  Indians  have  been  practically  deprived  of  their  accustomed  water- 
supply,  and  reduced  to  a  condition  of  dependence  upon  the  government 
for  bare  subsistence.  In  response  to  an  urgent  appeal  on  their  behalf  made 


PROJECTED  RESERVOIRS. 


321 


by  the  Indian  Agent  and  the  Commissioner  of  Indian  Affairs  to  the 
Secretary  of  the  Interior,  an  investigation  was  made  in  1896  by  Mr, 
Arthur  P.  Davis,  of  the  U.  S.  Geological  Survey,  of  the  feasibility  and 
cost  of  building  storage-reservoirs  to  supply  the  Indians.  The  sites  ex- 
amined and  reported  upon  were  the  Queen  Creek  site,  and  a  site  on  the 
main  Gila  River  at  the  Buttes,  14  miles  above  Florence. 

The  lack  of  suitable  apparatus  for  determining  the  depth  to  bed-rock 
at  these  sites  led  Mr.  Davis  to  recommend  that  "  thorough  exploration 
should  be  made  with  a  core-drill  before  beginning  the  construction  of  the 
dam.''  July  1,  1898,  an  appropriation  of  $20,000  was  made  to  continue 
the  investigation,  the  money  to  be  expended  by  the  Director  of  the  U.  S. 
Geological  Survey,  under  the  direction  of  the  Secretary  of  the  Interior. 
The  work  was  placed  in  the  hands  of  Mr.  Davis,  and  the  investigation 
thoroughly  outlined  by  him,  the  writer  acting  as  Consulting  Engineer; 
but  before  the  field-work  was  completed,  Mr.  Davis  was  obliged  to  resume 
his  studies  of  the  water-supply  of  Central  America  with  the  Isthmian 
Canal  Commission.  The  responsible  oversight  of  the  work  was  then  in- 
trusted to  Mr.  J.  B.  Lippincott,  whose  report  was  published  as  No.  33  of 
"  Water-supply  and  Irrigation  Papers."  The  report  of  the  writer  as  Con- 
sulting Engineer  was  transmitted  to  the  U.  S.  Senate,  as  Document  No, 
152,  56th  Congress,  1st  Session. 

In  conducting  these  investigations  the  depth  of  bed-rock  at  the  various 
sites  selected  was  tested  by  two  machines,  which  had  been  successfully 
used  on  the  Nicaragua  Canal,  and  were  loaned  by  the  Nicaragua  Canal 
Commission  for  the  purpose.  The  machine  consisted  of  a  light,  portable 
pile-driver,  by  which  pipe  from  2  to  1:  inches  diameter  could  be  driven 
through  sand,  gravel,  and  bowlders,  to  bed-rock,  with  a  diamond  core-drill 
for  penetrating  the  rock  and  bringing  up  a  core  for  testing  its  quality.  The 
cost  of  each  outfit  delivered  in  Arizona  was  about  $1600.  Six  men  were 
required  to  operate  each  machine  which  was  capable  of  boring  200  feet 
in  rock,  and  making  6  to  8  feet  per  day  in  hard  rock,  and  10  to  15  feet 
per  day  in  softer  rock.  The  average  cost  per  foot  of  drilling  done  was 
$2.46.  The  entire  amount  of  drilling  done  was  3254  feet,  of  which  322  feet 
was  in  rock.  Five  dam-sites  were  thus  tested,  as  follows:  Queen  Creek, 
The  Buttes,  The  Dikes^  Riverside,  and  San  Carlos. 

The  maximum  depth  to  bed-rock  at  the  Buttes  site  was  123  feet,  while 
at  the  Riverside  and  San  Carlos  sites  the  greatest  depth  was  found  to  be 
about  75  feet  below  the  surface. 

The  net  results  of  the  investigation  are  summarized  in  the  following 
conclusions  taken  from  the  report  of  the  writer: 

"  1st.  That  a  minimum  of  40,000  acre-feet  of  water  annually  should  be 
stored  for  the  supply  of  the  Indian  reservation. 

"2d  That  it  is  not  feasible  to  obtain  this  supply  from  Queen 


322        BESERYOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 

Creek,  although  the  dam  and  reservoir  proposed  on  the  stream  are  feasible 
of  construction  if  a  sufficient  water-supply  were  available. 

3d.  That  the  Gila  Eiver  is  the  only  available  source  of  permanent 
supply. 

"  4th.  That  it  is  not  feasible  or  advisable  to  build  a  dam  and  reser- 
voir on  the  Gila  for  storing  so  small  a  quantity  as  40,000  acre-feet  of 
capacity  on  account  of  the  rapidity  with  which  a  small  reservoir  must  be 
filled  with  silt. 

"  5th.  That  it  is  not  feasible  to  construct  a  reservoir  outside  of  the 
immediate  channel  of  the  Gila  of  sufficient  capacity  to  provide  for  the 
wants  of  the  Indians,  filling  the  same  annually  by  a  conduit  from  the 
river. 

"  6th.  That  it  is  not  advisable  to  build  a  dam  and  reservoir  on  the 
channel  of  the  river  of  less'  capacity  than  one-half  the  total  annual  flow 
of  the  river  in  minimum  years. 

"  7th.  That  feasible  reservoir-  and  dam-sites  exist  on  the  Gila  at  the 
Buttes,  Eiverside,  and  San  Carlos. 

"  8th.  That  it  is  not  feasible  to  build  a  masonry  dam  at  the  Buttes  on 
account  of  the  rotten  quality^,  of  the  rock,  the  great  depth  to  bed-rock, 
and  the  excessive  height,  of '"l^m^-i^qnired  to  obtain  a  storage  of  174,000 
acre-feet,  or  about  one-hajj  thy&inimum  flow  of  the  stream. 

"  9th.  That  a  combination  rock-fill  and  masonry  dam  is  feasible  to 
construct  at  the  Buttes  at  a  cost  of  $2,643,327,  storing  174,040  acre-feet, 
but  that  it  is  not  feasible  to  construct  a  dam  of  any  type  of  greater  height 
or  capacity. 

"  10th.  That  the  Buttes  reservoir  of  the  stated  capacity  may  be  ex- 
pected to  fill  with  solid  matter  in  eighteen  years,  unless  dredged  or  sluiced 
out. 

"  11th.  That  it  is  feasible  to  construct  a  masonry  dam  at  ^Eiverside  at 
a  cost  of  $1,989,605,  including  damages  for  right  of  way  and  the  cost  of 
diversion-dam  at  the  head  of  the  Florence  Canal,  forming  a  reservoir  with 
a  capacity  of  221,134  acre-feet. 

"  12th.  That  it  is  feasible  to  increase  the  height  of  the  Eiverside  dam 
at  least  70  feet  higher  than  the  one  estimated  upon,  giving  an  ultimate 
reservoir  capacity  of  about  650,000  acre-feet,  which  would  not  be  filled 
with  solid  matter  short  of  sixty-seven  years. 

"  13th.  That  it  is  feasible  to  construct  a  masonry  dam  at  San  Carlos 
at  a  cost  of  $1,038,926,  including  damages  for  right  of  way  and  the  cost  of 
new  diversion-dam  at  the  head  of  the  Florence  Canal,  forming  a  reservoir 
of  241,396  acre-feet  capacity;  that  the  water-supply  is  ample  to  fill  such 
a  reservoir  in  the  years  of  minimum  flow,  and  that  the  volume  of  storage 
will  irrigate  at  least  100,000  acres  in  addition  to  the  irrigation  of  the  lands 
of  the  Indians. 


322         RESERYOmS  FOR  IRRIGATION,  WATER-POWER,  ETC. 

Creek,  although  the  dam  and  reservoir  proposed  on  the  stream  are  feasible 
of  construction  if  a  sutlicient  water-supply  were  available. 

3d.  That  the  Gila  lliver  is  the  only  available  source  of  permanent 
supply. 

-ith.  That  it  is  not  feasible  or  advisable  to  build  a  dam  and  reser- 
voir on  the  Gila  for  storing  so  small  a  quantity  as  40,000  acre-feet  of 
capacity  on  account  of  the  rapidity  with  which  a  small  reservoir  must  be 
filled  with  silt. 

"  5th.  That  it  is  not  feasible  to  construct  a  reservoir  outside  of  the 
immediate  channel  of  the  Gila  of  sufficient  capacity  to  provide  for  the 
wants  of  the  Indians,  filling  the  same  annually  by  a  conduit  from  the 
river. 

"  6th.  That  it  is  not  advisable  to  build  a  dam  and  reservoir  on  the 
channel  of  the  river  of  less,  capacity  than  one-half  the  total  annual  flow 
of  the  river  in  minimum  years. 

"  7th.  That  feasible  reservoir-  and  dam-sites  exist  on  the  Gila  at  the 
Buttes,  Riverside,  and  San  Carlos. 

"  8th.  That  it  is  not  feasible  to  build  a  masonry  dam  at  the  Buttes  on 
account  of  the  rotten  quality^,  of  the  rock,  the  great  depth  to  bed-rock, 
and  the  excessive  height- of  ^^rn^required  to  obtain  a  storage  of  174,000 
acre-feet,  or  about  one-hajj'thyfeinimum  flow  of  the  stream. 

"  9th.  That  a  combiiiation  rock-fill  and  masonry  dam  is  feasible  to 
construct  at  the  Buttes  at  a  cost  of  $2,643,327,  storing  174,040  acre-feet, 
but  that  it  is  not  feasible  to  construct  a  dam  of  any  type  of  greater  height 
or  capacity. 

"10th.  That  the  Buttes  reservoir  of  the  stated  capacity  may  be  ex- 
pected to  fill  with  solid  matter  in  eighteen  years,  unless  dredged  or  sluiced 
out. 

"  11th.  That  it  is  feasible  to  construct  a  masonry  dam  at.Eiverside  at 
a  cost  of  $1,989,605,  including  damages  for  right  of  way  and  the  cost  of 
diversion-dam  at  the  head  of  the  Florence  Canal,  forming  a  reservoir  with 
a  capacity  of  221,134  acre-feet. 

"  12th.  That  it  is  feasible  to  increase  the  height  of  the  Eiverside  dam 
at  least  70  feet  higher  than  the  one  estimated  upon,  giving  an  ultimate 
reservoir  capacity  of  about  650,000  acre-feet,  which  would  not  be  filled 
with  solid  matter  short  of  sixty-seven  years. 

"  13th.  That  it  is  feasible  to  construct  a  masonry  dam  at  San  Carlos 
at  a  cost  of  $1,038,926,  including  damages  for  right  of  way  and  the  cost  of 
new  diversion-dam  at  the  head  of  the  Florence  Canal,  forming  a  reservoir 
of  241,396  acre-feet  capacity;  that  the  water-supply  is  ample  to  fill  such 
a  reservoir  in  the  years  of  minimum  flow,  and  that  the  volume  of  storage 
will  irrigate  at  least  100,000  acres  in  addition  to  the  irrigation  of  the  lands 
of  the  Indians. 


Fig.  140.— Contouu  Map  of  Buttes  Resehvoiu-site,  Gii,a  Rivek,  Akizona 


[To  face  page  323. 


I 


/ 


324 


RESERVOIRS  FOR  IRRIQATION,  WATER-POWER,  ETC, 


Fig.  142.— Section  of  Proposed  RoCKr^-iLL  .        -at  the  Bdttes,  Gila  River, 


Fig.  143. — Section  of  Proposed  Buttes-dam  through  Spillway,  showing  End 
Wall  of  Rock-pill,  Gila  River,  Arizona. 


UNOL 


324 


RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  BTO, 


Fig.  143. — Section  op  Proposed  RpCRr^-iLL. I) -.at  the  Bdttes,  Gila  River, 


Fig.  143. — Section  of  Proposed  Buttes-dam  through  Spillway,  showing  End 
Wall  of  Rock-fill,  Gila  River,  Arizona. 


Flu.  144,— Plan  of  Buttes  Dam-site,  showing  Location  sklected  fok  Rock-fill  Dam,  Gila  River,  Akizona. 

[To  Jace  page  3'25. 


imAMY 

OJ-  '1H£ 


Scale 


ConVour  inherval  10  fee*- 


PROJECTED  BESERVOma. 


327 


Fig.  149. — Maximum  Profile  op  Proposed  San  Caklos-dam  op  Masonry,  Gila 

EiVER,  Arizona. 


328         liESEliVOIES  FOU  IRRIGATION,  WATER-POWER,  ETC. 


Fia.  150. — Section  of  San  Caijt.os-dam  thkough  one  op  the  Outlet-towebs, 
Illustrating  Arrangement  of  Control. 


imAMY 


Fig.  laO. — Section  of  San  Cabt.os-dam  thkough  one  of  the  Outlet-towers, 
Illustrating  Arrangement  op  Oontrul. 


1 


..J 


330         RESERVOIRS  FOR  IRUIGA'IION,  WATER-POWER,  ETC. 

"  lilli.  Thai  it  is  feasible  to  construct  a  dam  at  San  Carlos  at  least  70 
feet  higher  tluin  that  contemplated  in  the  estimates,  forming  a  reservoir 
whose  ultimate  capacity  would  be  approximately  550,000  acre-feet,  and 
whose  probable  life  of  usefulness  would  be  sixty-three  years  before  be- 
coming filled  with  silt." 

Unquestionably  the  best  dam-site  yet  discovered  is  that  located  in  the 
narrow  canyon  immediately  below  the  San  Carlos  Apache  Indian  reserva- 
tion. The  walls  of  the  canyon  are  but  little  more  than  100  feet  apart  at 
the  level  of  the  river-bed,  and  are  composed  of  hard  limestone,  the  lowest 
stratum  being  a  pink  color,  and  the  upper  layers  dark  gray,  both  of  high 
specific  gravit}^,  and  affording  very  satisfactory  foundation  for  a  high 
masonry  dam.  The  maximum  height  of  dam  planned  for  this  location 
from  deepest  bed-rock  to  the  top  of  the  central  portion  of  the  dam  is  216 
feet,  and  the  maximum  length,  including  spillways,  is  617  feet.  The 
spillway  on  the  left  bank  is  excavated  almost  wholly  out  of  the  solid  clitf, 
and  is  128  feet  in  length.  That  on  the  opposite  side  of  the  dam  is  237  feet 
in  length,  and  is  approached  by  a  channel  excavated  largely  from  the 
mountainsides.  The  rock  from  these  spillways  will  be  used  in  constructing 
the  dam.  The  central  portion  of  the  dam  is  236  feet  long,  and  is  raised 
12.5  feet  above  the  crest  of  the  spillways.  The  latter  have  a  discharging 
capacity  of  57,000  acre-feet  at  that  depth.  Three  feet  additional  depth 
would  give  a  discharge  of  79,000  second-feet  over  the  spillways  and  1000 
second-feet  over  the  body  of  the  dam,  which  is  so  greatly  in  excess  of  the 
probable  volume  to  be  cared  for  in  flood,  owing  to  the  equalizing  effect 
of  the  large  reservoir  above,  that  no  water  will,  in  all  probability,  ever 
pass  over  the  central  portion  of  the  dam.  The  section,  however,  has  been 
planned  heavy  enough  to  withstand  the  shock  of  any  overflow  that  may 
occur  in  addition  to  the  normal  water-pressure.  The  crest  width  is  to  be 
16  feet,  and  the  extreme  base  183.6  feet. 

It  is  proposed  to  construct  the  dam  of  concrete  masonry  made  witn 
Portland  cement  ground  with  silica  and  to  constitute  what  is  known  as 
"  sand  cement,"  as  the  binding  material,  which  will  be  used  with  sand  and 
broken  stone  in  the  usual  manner.  In  the  body  of  the  concrete,  large 
blocks  of  stone  will  be  embedded  as  closely  together  as  possible  consistent 
with  a  perfect  ramming  of  the  concrete.  The  lines  of  pressure,  with 
reservoir  full  and  empty,  are  well  within  the  inner  third  of  the  dam,  result- 
ing in  a  safe  gravity  structure.  Expansion  and  contraction  are  provided 
for  by  arching  the  dam  up-stream.  The  maximum  pressure  on  the  down- 
stream toe  is  computed  at  12.5  tons  per  square  foot,  and  at  12  tons  per 
square  foot  on  the  upper  toe. 

The  outlets  to  the  (\f\m  are  to  be  made  throus^h  two  semicircular 
towers.  The  intakes  into  the  towers  are  a  series  of  elbows,  with  plain  cap 
or  cover,  six  in  number  to  each  tower,  each  3  feet  in  diameter. 


Fig.  152«.— San  Carlos  Dam-site,  looking  DowxN-feThEAM. 


Fia.  153  — BoiiiNU  Apparatus,  consisting  of  Pilk-dhivkr  and  Diamond-coee 
Dkii-l  at  Work.  Used  for  testing  Bed-rock  at  Gila  Kiver  Dam-sites, 
Arizona. 


Fig.  154.  — View  of  the  San  Carlos  Dam-site,  Gila  River,  Arizona, 


•V 


f         -  - 

BBjlfeimj;, 

IHI 

Fig.  154a.— View  of  Left  Abutment  Wall.  San  Carlos  Dam-site,  showing 

Dip  of  Limestone. 


Fig.  155a.— Buttes  Dam-site,  looking  Up-stream  from  Uppeii  Toe. 


Fig.  156.— Buttes  Dam-site,  looking  Up-stream  ;  Pkoposed  Quarries  on  Left  ; 
Spillway  on  Left  of  Center  of  Field. 

337 


PROJECTED  RESERVOIRS. 


339 


From  each  tower  two  48-inch  pipes  pass  through  the  dam,  discharging 
into  the  river-bed  below.  These  are  controlled  by  balanced  valves  placed 
inside  the  tower. 

The  reservoir  will  cover  an  area  of  6230  acres  at  the  130-foot  contour 
above  river-bed  at  the  dam,  to  a  mean  depth  of  39.2%  of  the  maximum. 
This  will  be  entirely  on  the  Apache  Indian  reservation,  and  will  flood  587 
acres  of  land  that  has  been  irrigated  and  farmed  by  the  Indians.  Of  the 
remaining  area,  4405  acres  are  irrigable  and  3360  acres  cannot  be  tilled. 
An  abundance  of  equally  good  land  on  the  reservation  can  be  provided  with 
^facilities  for  irrigation  above  the  reservoir-site.    The  estimate  includes 


Fig.  ioY. — View*  of  Rivei^side  Dam-site,  Gila  River,  Arizona. 


$20,000  for  these  substitute  works.  The  removal  and  reconstruction  of 
the  buildings  of  the  Indian  agency  is  estimated  to  cost  $60,000,  and  the 
rebuilding  of  five  miles  of  the  Gila  Valley,  Globe  and  Northern  Railway 
is  estimated  at  $50,000,  including  the  removal  of  two  bridges.  The  entire 
cost  of  the  dam  and  the  contingent  expenses  noted,  including  the  cost  of 
new  head-works  for  the  canal  to  convey  water  to  the  reservation,  located 
on  the  river,  60  miles  below,  is  estimated  at  $1,038,926,  or  $4.30  per  acre- 
foot  of  storage  capacity. 

For  the  details  of  the  entire  system  of  proposed  reservoirs  on  the 
Gila  River  the  reader  is  referred  to  the  able  and  interesting  report  of 
Mr.  J.  B.  Lippincott,  M.  Am.  Soc.  C.  E.,  in    Water-supply  and  Irrigation 


•i 


340         RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


Fig.  158.— Plan  of  Tonto  Dam. 


PROJECTED  RESERYOIBS. 


341 


Papers,"  No.  33,  from  which  the  cuts  illustrating  the  plans,  prepared  by 
Mr.  J.  H.  Quinton,  M.  Am.  Soc.  C.  E.,  in  collaboration  with  the  writer  and 
Mr.  Jippincott,  have  been  obtained  by  courtesy  of  the  Director  of  the 
U.  S.  Geological  Survey. 

The  manifest  duty  of  the  government  to  provide  a  water-supply  for  the 
impoverished  and  dependent  Indians,  which  will  enable  them  to  become 
again  self-supporting,  has  been  used  as  a  lever  to  commit  the  government 
to  the  policy  of  reservoir-construction  in  the  arid  West,  and  it  is  hoped 
by  the  advocates  of  this  policy  that  the  entering  wedge  will  be  formed 
"by  the  construction  of  the  San  Carlos  dam  on  the  Gila.  It  has  been  shown 
hy  Mr.  Lippincott's  report  that  sufficient  water  may  be  impounded  by  the 
dam  to  irrigate  over  100,000  acres  of  valuable  land  belonging  to  the 


Fig.  159. -Sections  of  Dam  and  Canyon  of  Tonto  Reservoir. 

governm.ent,  in  addition  to  supplying  the  Indians,  the  value  of  which,  with 
such  permanent  water-rights,  will  exceed  $5,000,000.  In  addition  the  ex- 
pense of  feeding  the  Indians,  amounting  to  $109,500  per  annum,  would  be 


The  relative  estimates  of  the  cost  of  the  dams  reported  upon  on  the 
Gila  River  show  that  the  Buttes  dam  would  cost  $15.19  per  acre-foot;  the 
Riverside  dam,  $9.01  per  acre-foot;  and  the  San  Carlos  dam,  $4.30  per 
acre-foot  of  storage  capacity. 

Tonto  Basin  Dam,  Arizona.— Of  all  the  reservoir  projects  for  irrigation- 
storage  in  Arizona,  the  largest  and  most  extensive  is  that  of  building  a 
high  masonry  dam  on  Salt  River,  and  converting  the  great  Tonto  Valley 


'e/i  60  ■ 


PEOJECTED  BESEBVOIRS. 


343 


into  an  enormous  reservoir,  covering  14,200  acres  and  impounding  over 
one  million  acre-feet  of  water.  The  dam  projected  will  be  200  feet  in 
height  above  the  ordinary  low-water  level  of  the  stream  (Figs.  158  and  159). 
The  extreme  height  of  the  dam  above  its  foundation  will  be  250  feet,  and 
its  length  on  top  will  be  647  feet,  measured  on  the  arc  of  its  curvature  up- 
stream, which  is  to  be  on  a  radius  of  818.5  feet. 

The  scheme  is  projected  by  the  Hudson  Canal  and  Reservoir  Company 
of  ^^ew  York,  and  is  a  combined  irrigation  and  electric-power  project,  the 


Fig.  161.— ToNto  Basin  Dam-site,  Salt  River,  Arizona,  looking  down- stream. 
The  Carriage  is  standing  on  the  Line  of  the  Dam. 


same  water  being  used  for  both  purposes.  The  estimated  cost  of  the 
reservoir  and  dam,  capable  of  storing  water  for  the  irrigation  of  500,000 
acres  of  land,  is  $2,450,000.  The  cost  of  the  electric  plant  and  transmis- 
sion lines  for  developing  and  delivering  6768  H.P.  is  estimated  at 
$1,152,000,  a  total  of  $3,602,000,  including  interest  on  capital  invested 
during  construction.  The  estimated  net  revenue,  based  partly  on  actual 
contracts,  is  $1,134,000  per  annum,  of  which  $560,000  would  be  derived 
from  the  sale  of  water  to  canal  companies  and  new  lands  in  the  lower  Salt 
River  and  Gila  River  valleys,  and  the  remainder  from  the  sale  of  power  to 
mining  companies. 


A 


344 


ItMSMItVOntS  FOn  IUIUGATIOH.  WA'/ER-POWBlt.  ETC. 


riio  out  n,e  or  ILo  rescrv,,!,-  (Ki,,.  l„„)  ,„  „,       j         ^„  y 
contour,  and  tl,e  ult.nate  l.e.ght  of  the  wat.r-lovol  wHl  cover  a  much  greate;. 
surface  timn     shown  by  the  map.   Mr.  A.  1'.  Man,  Chief  Engineer  of  tl,e 

.tn     hiel  "      :™«*'""  «^  I'l^l^fe-aphy  of  the  basin, 

uoni  wJucli  tlic  tollowmg  data  are  compiled: 

The  area  of  the  watershed  above  the  dam  is  C2C0  square  miles-  the 
elevation  of  the  l,ase  of  the  dam  at  low-water  level  .s  1925  feet  above  t.de! 
^^ater.  The  maximum  altitude  of  the  watershed  is  about  7000  feet  and 
the  mean  precipitation  upon  the  shed  is  estimated  at  23  mches  per  annum, 
ihe  run-off  for  seven  years  has  been  computed  as  follows- 


Year. 

Acre-feet. 

Year. 

Acre-feet. 

1889 
1890 
1891 
1892 

1,111,790 
1,659,726 
1,999,092 
66y,02o 

1894 
189.3 

297.704 
1.124,196 

Mean  

1,125,466 

.  """iu  lepresenr  aoout  10  per  cent  of  a 

n  ean  precipatation  of  23  inches.    The  maximum  flood  yet  r  corded  thai 

have  filled  the  spillways  to  a  depth  of  22  feet,  while  the  crest  of  the  dam 
.s  intended  to  be  13  feet  higher  than  this  miximum-flood  height.  Ma™ 

t^sMTZ  164    ''''' '""^  "^'^  ™-  ^- 

from  the  records  of  gaugmgs  made  of  the  streams  at  177  acre-feet  per 
rest;:   ^""Tf'  "'"^  ''''  '""^         ^'^-^  ^ 

iess  due  to  the  great  elevation  of  the  Salt  River  shed 

Salt'Jivrr'tnl  "/T'''  f"'*  ''^''  ''^  ^"  ^"'g^t-^  the  lower 
bait  Eiver  valley,  for  the  reason  that  their  present  supply  from  the  normal 

so  that  the  full  productive  capacity  of  their  lands  can  only  be  reached  bv 
having  a  supply  of  stored  water  to  draw  upon  during  the  low-water  sta.e 
of  he  river.  The  canal  companies  are  eager  to  purchase  all  the  reservoired 
water  to  insure  a  constant  supply.   The  reservoir  company  is  thus  in  the 
or  unate  position  of  being  able  to  sell  their  water  at  wholesale  to   n  e 
tabkshed  communrty  of  irrigators,  who  are  in  urgent  need  of  the  si  pp  - 

pnse.  The  majority  of  such  large  projects  have  to  meet  with  the  lon.^ 
de  ay  incident  to  the  settlement  of  the  country,  which  they  are  to  p  oWd^ 
with  water  before  any  adequate  revenue  can  be  derived  from  it  Durin! 


II8RARY 


Fig.  163.— Map  of  Gila  and  Salt  Kivjer  Valleys 


NG  Existing  and  Pkoposbd  Iiuugation  Woeks. 


[To  face  page  346. 


Yim  OaNALS  CoN^TliXJCTED  AND  PllQPOSEP, 


[To  face  page  847, 


v 


1 


348         liESKRVOJliS  FOR  IIUUGATION,  WATEU-POWER,  ETC. 

this  ])eri()(l  of  waiting  tlio  interest  account  accumulates,  and  if  this  cannot 
be  met,  the  enter])rise,  thougli  intrinsically  meritorious,  is  destined  to 
failure. 

Projected  Reservoirs  on  the  Rio  Verde,  Arizona.— The  Eio  Verde,  which 
has  a  watershed  of  GOOD  square  miles  above  its  junction  with  the  Salt 
Elver  of  Arizona,  supplies  a  large  surplus  flood  flow,  which  the  Eio  Verde 
Canal  Company  is  organized  to  utilize  as  far  as  possible.  The  principal 
-reservoir-site  is  located  some  40  or  more  miles  above  the  mouth  of  the 
stream,  and  is  called  the  "  Horseshoe  reservoir,"  where  a  dam  170  feet  in 
height  will  close  a  reservoir  of  205,000  acre-feet  capacity  (Fig.  165).  The 
length  of  this  dam  will  be  1250  feet  on  top,  the  length  at  the  stream-bed 
being  360  feet.  Soundings  taken  along  the  line  of  the  dam  indicate  that 
the  greatest  depth  to  bed-rock  is  24  feet  below  low-water  line,  which  will 
therefore  make  the  extreme  height  of  dam  194  feet.  A  spillway  1000  feet 
long,  over  a  solid  rock  ledge,  located  2200  feet  away  from  the  dam,  is  a 
commendable  feature  of  the  work. 

The  elevation  of  the  top  contour  of  the  reservoir  is  2052  feet  above 
tide-level,  and  it  covers  an  area  of  3402  acres.  Water  released  at  the  dam 
will  flow  down  the  river-channel  for  25  miles  to  a  diverting-dam,  70  feet 
high  and  480  feet  long  at  the  crest-line,  of  which  the  elevation  is  1614 
feet  above  sea-level.  Both  dams  are  of  the  same  type— rock-fills  with  a 
facing  of  asphaltum  concrete.  A  canal  with  a  capacity  of  800  second-feet 
starts  at  the  lower  dam  and  skirts  the  northern  edge  of  the  Salt  Eiver 
Valley,  practically  parallel  with  the  Arizona  Canal,  but  extending  far  be- 
yond the  lower  end  of  the  latter.  It  is  to  be  69  miles  in  length,  of  which 
25  miles,  from  the  mountains  to  Cave  Creek,  are  practically  completed. 
The  outlet-tunnel  to  the  Horseshoe  reservoir,  715  feet  long,  through  solid 
granite  rock,  is  also  finished.  It  is  12  feet  wide  and  13  feet  high,  and  has 
a  gate-shaft  near  its  upper  end  for  controlling  the  supply  to  the  canal.  The 
estimated  cost  of  the  work  is  as  follows: 


Horseshoe  reservoir   . 

Diverting-dam  

Main  canal  to  New  Eiver  

Extension  of  main  canal,  19  miles 
Miscellaneous  


  $1,600,000 

The  area  of  tillable  land  above  the  highest  canals  that  would  be  irri^ 
gated  by  the  works  herein  mentioned  (which  are  only  those  noted  in  the 
company's  prospectus  as  the  works  to  be  built  on  "Initial  Construction") 
IS  given  as  220,000  acres,  of  which  15,000  acres  are  in  the  Verde  Valley  and 


$600,000 
200,000 
560,000 
180,000 
60,000 


PROJECTED  BESEBVOIRS. 


349 


Fig.  166.— Map  of  Lower  Portion  of  McDowell  Reservoir. 


850        liESERVOlliS  FOR  IIUUGATION,  WATEll-POWEli,  ETC. 

may  form  a  part  of  another  reservoir  to  be  built  by  the  Arizona  Improve- 
ment Company,  110,000  acres  are  between  ohl  Fort  McDowell  and  the 
Agua  Fria  Elver,  and  95,000  acres  are  west  of  the  Agua  Fria. 

The  plans  of  the  company  also  contemplate  the  construction  of  the 
following:  A  reservoir  on  New  Kiver,  to  be  fed  by  the  canal  and  the  rather 
limited  drainage  of  the  stream,  and  to  have  a  capacity  of  133,500  acre-feet, 
covering  3416  acres;  "Reservoir  No.  3,''  covering  1000  acres,  with  a 
capacity  of  10,000  acre-feet;  and  "  Eeservoir  No.  V  with  an  area  of  2493 
acres  and  a  capacity  of  68,093  acre-feet.  The  cost  of  these  is  not  included 
in  the  above  estimate.  The  entire  system  will  cost  from  $3,000,000  to 
$4,000,000.  All  of  the  dams  proposed  are  to  be  of  the  rock-fill,  asphaltum- 
'Covered  type. 

The  company  proposes  to  guarantee  to  the  irrigators,  in  their  water- 
right  contracts,  the  delivery  to  them  of  2  acre-feet  per  acre,  if  demanded, 
in  any  one  irrigating  season;  if  more  water  is  required,  it  will  be  paid  for 
extra,  and  the  company  does  not  guarantee  to  furnish  it  if  there  is  a 
shortage.  The  annual  rates  are  to  be  on  a  sliding  scale  of  increase  up  to 
the  eleventh  year,  when  the  maximum  will  be  $2.42  per  acre-foot,  the  first 
two  years  being  one-half  that  rate.  Water-rights  are  sold  at  $10  per  acre, 
of  which  $1  is  paid  down  and  $1  per  acre  per  annum  thereafter  until  fully 
paid,  with  8  per  cent  interest  on  deferred  payments. 

McDowell  Reservoir  Project,  Arizona.— The  Arizona  Improvement 
Company,  the  owner  of  the  Arizona  Canal,  which  heads  in  Salt  River  half 
a  mile  below  the  mouth  of  the  Verde,  has  in  contemplation  the  erection  of 
a  storage-reservoir  dam  a  short  distance  above  the  mouth  of  the  Verde, 
on  the  Verde  River,  to  afford  a  means  of  fortifying  their  canal  during  low- 
water  periods.  The  reservoir  (Fig.  166)  will  flood  a  large  part  of  the 
abandoned  military  reservation  of  Fort  McDowell,  from  which  it  takes  its 
name.  The  capacity  of  the  reservoir  is  computed  by  Mr.  F.  P.  Trott, 
county  surveyor,  of  Phoenix,  as  15,000,000,000  cubic  feet,  or  344,350  acre- 
feet.  The  height  of  dam  proposed  is  140  feet;  extreme  length,  1594 
feet.  A  spillway,  800  feet  long  and  10  feet  deep,  will  be  excavated  in  the 
crest  of  a  ridge  of  rock  east  of  the  dam.  The  computation  of  contents  is 
made  from  a  contour-line  run  at  114  feet  above  the  low-water  level  at  the 
dam,  or  1430  feet  above  tide.  Bed-rock  is  exposed  across  the  site  with 
the  exception  of  200  feet,  where  soundings  made  with  rods  locate  it  at  a 
depth  of  from  1  to  22  feet  below  the  surface.  Plans  for  the  dam  have  not 
been  definitely  adopted,  and  no  estimates  of  cost  have  been  made. 

Bear  Canyon  Dam,  near  Tucson,  Arizona.— The  Santa  Catalina  range  of 
mountains,  a  few  miles  north  of  Tucson,  Arizona,  reaches  to  an  altitude 
of  over  10,000  feet,  in  the  culminating  peak  called  Mt.  Lemon.  From  the 
southern  slopes  of  this  mountain  two  torrential  streams  of  considerable 
magnitude  at  times  debouch  into  the  valley  12  miles  from  Tucson.  These 


PBOJEGTED  BESERVOIES. 


351 


.nre  called  Bear  and  Sabina  canyons.   The  Catalina  Keservoir  and  Electric 
Company,  of  Tucson,  has  projected  a  high  dam  in  Bear  Canyon,  to  impound 
the  waters  of  these  streams,  diverting  a  fork  of  Sabina  into  the  reservoir 
The  dam  will  be  of  masonry,  200  feet  in  height,  and  will  require  about 
90,260  cubic  yards  of  masonry  to  construct  it.   The  width  between  the  solid 
.ranite  walls  of  the  canyon  is  but  20  feet  at  base,  130  feet  at  the  50-foot 
level  230  feet  at  the  100-foot  level,  and  435  feet  at  the  crest  of  the  dam. 
The  Vail  will  be  arched  up-stream  on  a  radius  of  400  feet.    The  reservoir 
will  cover  214.8  acres,  and  impound  14,762  acre-feet  of  water.   The  outlet 
will  be  placed  50  feet  above  the  base  of  the  dam,  discharging  into  a  cement- 
pipe  conduit,  32  inches  diameter,  3.65  miles  long,  laid  on  a  grade  of  3  feet 
per  1000     This  pipe  will  connect  with  the  head  of  a  steel  pressure-pipe, 
22  inches  in  diameter,  5000  feet  long,  laid  down  the  slope  of  the  mountain 
to  the  power-house,  with  a  total  drop  of  1470  feet.   This  fall  will  be  utilized 
to  generate  power,  which  will  be  transmitted  electrically  to  Tucson  and 
Ticinity,  where  it  is  worth  $150  per  H.P.  per  annum.   The  average  available 
power  to  be  delivered  for  sale  is  estimated  at  2445  H.P. 

The  water  will  be  used  for  irrigating  land  in  the  vicinity  of  the  power- 
house to  the  extent  of  about  4000  acres. 

The  cost  of  the  project  is  estimated  by  the  writer  as  follows: 

T   $596,530 

Masonry  dam   ^  81  210 

Power  conduit   45'764 

Pressure-pipe   :  •  : '  '  *  : 1  on^-io 

Power-stations  and  transmission-lmes  

Total   $843,844 

The  net  revenue  is  estimated  at  about  $100,000,  on  the  basis  of  using 
but  one-half  the  storage  capacity  of  the  reservoir  in  any  one  year. 
The  elevation  of  the  base  of  the  dam  above  sea-level  is  4200  teet. 
Proposed  Reservoirs  on  the  Rio  Grande.-T/i.  El  Paso  InternaUonal 
Dam -The  impounding  of  water  on  the  Kio  Grande  Eiver  at  El  Paso, 
Texas  has  long  been  discussed  as  an  international  enterprise  to  be  jointly 
entered  into  by  the  governments  of  the  United  States  and  Mexico  for  the 
purpose  of  making  a  division  of  the  river  for  irrigation  purposes  on  either 
side  of  the  international  boundary.   The  Mexican  authorities  have  claimed 
a  grievance  against  the  American  people  on  account  of  the  absorption  of 
the  stream  in  Colorado  and  I^ew  Mexico,  by  means  of  which  their  irrigation- 
supply  has  in  recent  years  been  greatly  impaired  and  diminished,  and  repre- 
sentations  have  been  made  to  the  effect  that  the  stream  should  be  either 
permitted  to  flow  as  it  was  wont  to  do  when  the  Mexican  canals  were  first 
used  or  that  the  flood-waters  should  be  impounded  by  a  reservoir  of  large 
capacity  at  the  expense  of  the  American  people,  and  the  wonted  supply 


352 


ltB:<MltVOntti  FOR  imtlQATlON,  WAmU'OWIili,  MTC. 


freely  furmshed  to  the  Mexican  canals  as  of  yore.   A  survey  of  a  mammoth 
reservo:r-sate  was  n,a,lc  in  t.S8.  by  Major  An«on  Mill„/u,  S.  ZZ^. 
Corp.,  the  s.te  ol  the  dan,  being  h.cated  a  «h„rt  distance  above  ElCo 
n  An.er^can  terntory    A  n.asonry  dan.  was  here  proposed,  to  be  65  feet' 
lugh  above    l,e  nver-bottom,  the  construction  of  which  ;ouId  create  a 
eservcr  14.5  mdes  long  by  4  miles  maximum  w.dth,  with  a  surface      a  of 
26,000  acres,  an  average  depth  of  23.6  feet,  and  a  capacity  of  537  000  acre 
eet.    The  estimated  cost  is  a  Httle  over  $300,000,  to  which  mus  '  be  added 
«>e  cost  of  removing  the  tracks  of  the  Southern  Pacific  and  the  Atchison 
Topeka  and  Santa  Fe  radroads,  which  traverse  the  basin  for  a  number  of 
miles  below  the  water-level,  and  their  reconstruction  on  higher  ground 
above  the  flow-hne.    This  was  estimated  to  cost  $590,000,  while  the  and. 
overflowed  were  valued  at  about  $69,000.    The  totil  investmen  wouS 
therrfore  e  about  $1,060  000.   This  work  has  never  been  undertaken 

The  EUphant  Butte  Dam.-Othev  sites  for  water-storage  in  lar^e  vol 
nme  were  known  to  exist  in  the  Rio  Grande  Valley  between  San  Mar  al 
nd  El  Paso  and  m  1890  two  of  them  were  surveyed  and  segregated  by  he 
o^'  the  U  %  r  J'-y       <3-"il^«d  -  the  18th  Innnal  Eepor 

3    and^9  '"'^""'^'^      reservoir-sites  L. 

38  and  39.    Site  No.  38  forms  a  lake  of  5540  acres,  having  a  storaire  cn 
pacity  of  175,000  acre-feet,  with  a  dam  80  feet  high.    The  1  ngth  ff  the' 
reservoir  is  31  miles,  its  maximum  width  a  little  lefs  than  2  m  fe    and  U 
me^i  depth  31.7  feet,  or  39.5%  of  the  maximum.   The  dam-site  Is  located 

40  feett  f  i         '        '  '0'^  foundation.  A  dam 

40  feet  high  to  the  water-line  would  here  form  a  reservoir  covering  6380 
acres^  with  a  capacity  of  102,000  acre-feet,  having  a  mean  depth  of  l'  et 
N  arly  midway  between  these  sites  is  the  location  selected  by  the  Bio 
Grande  Dam  and  Irrigation  Co.  for  the  erection  of  a  masonry  dL  called 
be  Ekphant  Butte,  from  its  proximity  to  a  well-known  landmark  on  the 
river  by  that  name.    This  corporation  was  organized  in  1893,  and  its  pr  n! 
cipal  offices  and  stockholders  are  in  London,  England.    Th   plans  of  the 
^mpany  are  very  comprehensive  and  contemplate  the  irrigation  of  th 
Val  Paraiso  above  Rineon,  the  Mesilla  Valley,  reaching  from  Fort  Selden 
0  El  Paso,  and  the  lands  below  EI  Paso  on  the  Texas  s^e  of  the  border  as 
far  down  as  Fort  Quitman,  Texas,  in  all  some  230,000  acres.    Thus  th 
f  thTllr  t '"r^'  by  Reservoir  Site  No.  39,  and  the  reservoir  basin 
of  the  International  dam  above  El  Paso,  are  proposed  to  be  irria-ated  Of 

ten    fashion  7         T'T"'  '  -t^-''^- 

The  c  ns  nit  ro  Tb       ^'°'-''.^"<'.^-""-       ^l-li-S  the  flood-flow, 
construction  of  the  reservoir  ,s  expected  to  provide  facilities  for  the 


PROJECTED  RESERVOIRS. 


35a 


complete  irrigation  of  these  lands  as  well  as  the  larger  areas  of  fertile, 
iintilled  valley  soil  commanded  by  the  new  system. 

The  Elephant  Butte  dam  is  located  112  miles  above  El  Paso  at  a  point 
Avhere  the  river  enters  a  narrow  canyon,  300  feet  in  width  between  sand- 
stone walls,  at  the  level  of  the  river-bed.  On  the  right  bank  the  wall  rises 
abruptly  250  to  300  feet  above  the  river,  while  on  the  left  the  height  is  95 
feet  to  a  flat  bench,  450  feet  wide,  which  is  to  be  utilized  as  a  spillway. 
The  dam  will  be  100  feet  high,  the  crest  being  10  feet  thick  in  center  and 
16  feet  thick  at  abutments.  The  thickness  of  the  base  will  be  63.5  feet  at 
center  and  66.5  feet  at  the  sides  of  the  stream-bed.  The  length  will  be 
570  feet,  on  a  curve  of  637  feet  radius,  at  the  upper  face,  which  will  be 
vertical.  The  bed  of  the  canyon  at  the  site  is  covered  with  large  limestone 
bowlders,  but  the  surface  indications  lead  to  the  belief  that  solid  bed-rock 
will  be  found  not  deeper  than  10  feet  below  the  top  of  these  bowlders. 
The  elevation  of  the  dam  is  4325  feet  above  sea-level  at  the  crest. 

The  dam  is  estimated  to  contain  49,980  cubic  yards  of  rubble  masonry 
and  1005  cubic  yards  of  concrete,  and  to  cost  $281,515,  including  founda- 
tions, outlet-pipes,  sluice-gates,  and  valves.  The  spillway  is  designed  to  be 
cut  in  solid  rock,  450  feet  wide,  with  a  sill  placed  15  feet  below  the  crest 
of  the  dam.  The  capacity  of  the  spillway  is  computed  at  108650  second- 
feet,  at  10  feet  in  depth,  which  is  regarded  as  ample,  in  view  of  the  fact 
that  the  maximum  recorded  discharge  of  the  river  at  El  Paso  is  less  than 
17,000  second-feet. 

The  outlets  of  the  dam  are  planned  to  have  a  maximum  discharging 
capacity  of  1200  second-feet,  and  consist  of  ten  cast-iron  pipes,  40  inches 
in  diameter,  passing  through  the  dam  at  the  bottom,  in  parallel  lines,  6 
feet  apart  between  centers.  These  pipes  are  reduced  at  the  upper  end  by 
short  reducers  to  30  inches  in  diameter  at  the  gates.  The  gates  are  to 
consist  of  hinged  flap-valves  of  cast  iron,  resting  on  seat-rings  of  bronze, 
and  are  to  be  raised  by  iron  screws  reaching  to  the  top,  the  motion  of  the 
valve  extending  over  an  arc  of  90°.  An  ingenious  cylinder  for  controlling 
the  motion  of  the  valve  and  preventing  it  from  suddenly  opening  or  closing 
by  the  eddying  currents  of  outrushing  water  is  attached  to  the  valve  in  the 
form  of  a  quadrant,  with  a  loose-fitting  piston  which  allows  water  to 
escape  from  the  cylinder  slowly.  Between  each  of  the  gates  a  pilaster  is 
built  the  full  height  of  the  dam,  eleven  in  all,  projecting  from  its  face  5J 
feet.  These  pilasters  are  grooved  near  the  outer  face,  sufficiently  to  receive 
a  series  of  loose  flashboards,  or  check-planks  of  cast  iron,  which  slide  up 
and  down  in  the  grooves.  When  these  check-planks  are  in  place  they  form 
open  chambers  from  top  to  bottom,  called  penstocks,  which  separate  the 
water  supplied  to  each  gate  from  the  others.  These  penstocks  are  2  X  3 
feet  in  dimension,  and  are  lined  throughout  with  cast  iron.  The  water 
enters  them  by  overflowing  the  top  of  the  check-planks,  of  which  a  suf- 


354        EESERVOUiS  FOR  IIIRIGATION,  WATER-POWER,  ETC. 


ficient  number  are  left  out  to  give  the  required  depth  of  overflow.  As  the 
reservoir  lowers,  additional  planks  are  removed.  When  these  planks  are 
placed  so  as  to  reach  above  the  level  of  the  water  each  penstock  forms  a 
shaft,  through  which  a  man  can  descend  to  the  gate  below  to  make  repairs. 
The  check-planks  are  2  feet  square,  and  rest  on  bronze  seats.  They  are  put 
in  place  and  removed  by  a  carriage  sliding  down  in  the  same  grooves,  and 
provided  with  automatic  clutches  that  engage  in  lugs  cast  upon  the  sides  of 
the  planks,  near  the  top.  This  carriage  is  hoisted  and  lowered  by  means  of 
a  geared  hand-hoist,  placed  over  the  penstock  at  the  top  of  the  dam.  The 
plan  thus  contemplates  drawing  off  water  from  the  top  of  the  reservoir  at 
all  times. 

An  alternative  plan  provides  for  closing  the  pipes  by  means  of  circular 
gates  fitted  with  roller  bearings  to  reduce  friction.  These  can  be  raised 
entirely  to  the  top  and  removed  if  desired. 

On  Fig.  167  is  shown  a  plan  of  the  dam-site  locating  the  position  of 
the  dam  and  spillway,  a  profile  of  the  masonry  structure  designed  with 
lines  of  pressure,  reservoir  full  and  empty,  and  a  cross-section  of  the  dam- 
site  and  spillway. 

The  Reservoir. — The  reservoir  formed  by  the  dam  is  25  miles  long  on 
the  75-foot  contour,  covers  an  area  of  7965  acres,  and  has  a  capacity  of 
253,368  acre-feet.  (See  Fig.  168.)  It  reaches  to  the  dam-site  of  the  U.  S. 
Ees.  Site  No.  38.  Of  the  lands  embraced  in  the  reservoir,  2549  acres  are 
public  lands,  while  those  in  private  ownership  cover  5416  acres  and  are 
valued  at  $7517. 

The  dip  of  the  rock  strata  is  toward  the  river  from  each  side.  The 
sandstone  when  tested  developed  a  weight  of  147  to  160  lbs.  per  cubic  foot, 
and  a  crushing-strength  of  216  to  360  tons  per  square  foot. 

From  the  dam  the  water  will  be  released  into  the  channel  of  the  river, 
which  it  will  follow  for  6  miles  to  a  diverting-weir  at  the  head  of  Paradise 
Valley.  This  weir  is  to  be  built  of  rubble  masonry,  faced  with  cut-granite 
blocks,  and  have  300  feet  of  overfall  for  the  passage  of  floods.  Here  are 
placed  the  head-gates  of  a  canal  to  be  constructed  for  the  irrigation  of 
40,000  acres  of  Paradise  Valley,  in  a  solid  rock  cut,  affording  rock  for  the 
construction  of  the  dam. 

Below  Paradise  Valley  the  river  is  again  inclosed  in  a  rocky  canyon, 
near  the  lower  end  of  which  a  second  diversion-weir  is  located,  the  con- 
struction of  which  has  begun,  as  shown  in  Fig.  169.  This  dam  is  5^  miles 
above  Fort  Selden,  N".  M.,  and  about  50  miles  below  the  storage-reservoir 
at  Elephant  Butte.  Its  purpose  is  merely  the  diversion  of  water  for  the 
irrigation  of  the  Mesilla  Valley,  extending  from  Fort  Selden  to  El  Paso. 
It  is  a  concrete  structure,  combining  an  overfall  waterway  for  the  passage 
of  the  river,  and  head-gates  for  the  canal.  The  height  of  the  crest  of  the 
overflow-weir  is  5  feet  above  the  river-bed,  or  the  exact  depth  of  the  water 


PROJECTED  BE^EKVOIBS. 


355 


TO 


PROJECTED  RESERVOIRS. 


359 


in  the  canal,  whose  grade  is  coincident  with  the  bed  of  the  river.  The 
length  of  the  weir-channel  is  300  feet.  The  thickness  of  the  concrete  at 
base  is  20  feet,  and  the  crest  is  in  the  form  of  a  rollerway  curve.  The 
abutments  are  7  feet  high  above  the  crest  of  the  weir.  The  water  is  ad- 
mitted to  the  canal  through  six  cast-iron  pipes,  48  inches  diameter,  set  in 
a  concrete  wall,  and  closed  with  sluice-gates.  The  entire  structure,  includ- 
ing wing  walls  and  abutments,  is  founded  on  piles,  driven  by  hydraulic 
jet  into  the  sand  bed  of  the  river,  and  inclosed  with  triple-lap  sheet-piling 
above  and  below.  Fig.  169  gives  a  view  taken  during  construction.  The 
weir  is  estimated  to  contain  2450  cubic  yards  of  concrete  and  to  cost 
$19,653.50. 

A  third  diversion-weir,  to  be  built  of  masonry  on  bed-rock  foundation, 
is  also  contemplated  for  the  supply  of  canals  below  El  Paso,  the  location 
selected  being  the  site  of  the  proposed  "  international  dam,"  5  miles  above 
El  Paso.  It  is  believed  that  the  latter  structure,  as  originally  contem- 
plated, will  never  be  built,  but  that  the  Elephant  Butte  dam,  when  finished, 
will  serve  as  an  efficient  substitute,  at  less  cost,  and  without  interference 
with  the  railways. 

Some  200  miles  of  main  canal  and  primary  laterals  are  projected  from 
the  two  diversion-weirs  above  El  Paso.  The  entire  enterprise  is  estimated 
as  follows: 

Elephant  Butte  storage-dam   $281,515 

Diversion-weir,  6  miles  below   27,874 

Diversion-weir,  50  miles  below   19,653 

Canal  system  above  Rincon,      M   75,749 

Canal  system  in  Mesilla  Valley   249,682 

Canal  system  below  El  Paso   196,000 

Total   $850,473 

This  is  an  average  cost  of  $3.70  per  acre  for  the  230,000  acres  to  be 
supplied  with  water,  although  the  estimate  does  not  include  the  divertmg- 
dam  near  El  Paso. 

Construction  began  in  1897  with  the  concrete  weir  near  Fort  Selden, 
but  has  been  interrupted  by  litigation.  From  this  weir,  a  canal  34  feet 
wide  on  bottom,  5  feet  deep,  on  a  grade  of  1 :  5000,  was  excavated  7  miles 
down  the  west  side  of  the  Rio  Grande  Valley,  where  it  was  carried  across 
the  river  by  a  series  of  four  inverted  siphon  pipes,  50  inches  m  diameter, 
laid  in  a  trench  11  feet  below  the  bed  of  the  stream.  These  pipes  are 
made  of  long-leafed  Texas  yellow-pine  staves,  held  in  place  with  round 
rods  of  steel  at  intervals  of  12  inches  from  center  to  center.  They  are 
each  388  feet  long,  and  have  a  fall  of  3.06  feet  from  the  water-level  m  the 
canal  on  the  west  side  to  that  of  the  canal  on  the  east.  They  pass  through 


300 


liKSKliVOlllS  FOR  lltRlGATION',  WATER-POWER,  ETC. 


wooden  bulkheads  or  wing  walls,  wliich  confine  the  river  on  either  side  to 
its  natural  hanks.  They  have  a  combined  capacity  equal  to  that  of  the 
canal,  or  4G5  cubic  feet  per  second.  The  plan  of  the  crossing  and  the 
method  of  construction  are  well  illustrated  by  the  accompanying  photo- 
graph, Fig.  170. 

The  chief  engineer  of  this  work,  which  when  completed  will  be  one  of 
the  most  important  and  extensive  irrigation  projects  in  the  arid  region, 
is  Mr.  J.  L.  Campbell  of  El  Paso. 

r     "     ~  — '  — — ^ — — 


Fig.  170. — Wood-stave  Pipes,  laid  under  Bed  of  the  Rio  Grande,  for 
SIPHONING  Canal  across  the  River,  by  Rio  Grande  Dam  and  Irrigation 
Company. 


Water-supply  of  the  Rio  Grande  at  El  Paso. — Gaugings  of  the  flow  of 
the  Eio  Grande  River  at  El  Paso,  made  by  the  U.  S.  Geological  Survey 
and  published  in  their  annual  reports  since  1890,  give  the  following  data 
of  the  discharge  of  the  stream: 

May  10,  to  Dec.  31,  1889  (no  flow  during  the  months  of 

August,  September,  October,  or  November)....     367,266  acre-feet 

1890,  flowing  the  entire  year   963,466  " 

1891,  January  to  June,  inclusive   1,567,173 

1897,  stream  dry  during  a  part  of  August  and 

September   1,360,360 


PROJECTED  RESERVOIRS. 


361 


From  these  data  it  is  apparent  that  the  reservoir  at  Elephant  Butte 
-would  have  filled  during  any  one  of  the  years  during  which  these  gaugings 
were  made. 

Gaugings  made  at  San  Marcial,  some  50  miles  above  Elephant  Butte, 
give  the  following  as  the  discharge  of  the  stream  at  that  point: 


1895,  February  to  August,  inclusive.. . 

1896,  February  to  December,  inclusive 

1897,  February  to  December,  inclusive. 


1,246,509  acre-feet 

541,499 
2,315,257 


In  1897  the  stream  was  practically  dry  during  August  and  September, 
yet  the  total  discharge  of  the  year  was  sufficient  to  have  filled  the  Elephant 
Butte  reservoir  nearly  ten  times. 

In  comparing  the  discharges  given  in  1897  at  San  Marcial  with  those 
at  El  Paso,  nearly  200  miles  below,  one  cannot  but  be  struck  with  the 
enormous  loss  of  water  in  the  stream  in  traversing  that  distance,  amount- 
ing to  854,897  acre-feet  during  the  year,  or  38.5%  of  the  total  flow.  A 
small  part  of  this  may  be  due  to  the  diversions  for  irrigation  and  to 
•evaporation,  but  the  greater  portion  must  find  some  subterranean  escape. 
A  possible  explanation  of  this  source  of  loss  is  given  in  the  following  ex- 
tract from  the  printed  report  of  Mr.  J.  L.  Campbell  upon  the  Elephant 
Butte  reservoir  site.   He  says  (p.  9) : 

"  Barring  the  existence  of  possible  subterranean  fractures,  open  suf- 
ficiently to  carry  away  considerable  amounts  of  water,  the  character  of  the 
reservoir-site  topographically  and  geologically  is  peculiarly  adapted  for 
storage  purposes.^^ 

These  fissures  may,  and  probably  will,  in  time  be  entirely  closed  by 
the  deposit  of  silt  in  the  reservoir,  and  thus  the  supply  may  be  augmented 
by  the  prevention  of  this  source  of  loss. 

The  Silt  Problem. — From  118  samples  of  the  water  of  the  Eio  Grande, 
taken  by  Major  Anson  Mills  at  El  Paso,  the  conclusion  was  reached  that 
the  silt  carried  in  suspension  averaged  0.345  of  1%  of  the  volume,  or  in 
other  words  1  acre-foot  for  each  290  acre-feet  of  water.  The  determina- 
tions of  the  Geological  Survey  during  1889  and  1890  at  the  same  point 
show  a  somewhat  less  percentage.*  It  is  there  stated  that  "  the  total  sedi- 
ment for  the  year  ending  June  30,  1890,  is  in  round  numbers  3,830,000 
tons;  this  earth,  at  a  weight  of  100  lbs.  per  cubic  foot,  would  cover  a  square 
mile  2f  feet  in  depth." 

This  would  be  equivalent  to  1760  acre-feet  of  sediment,  and  as  the 
discharge  of  the  river  during  this  period  was  820,425  acre-feet,  the  ratio 
of  silt  to  water  is  therefore  as  1  to  466.   A  mean  of  these  ratios  would 


*  llth  Annual  Report,  U.  S,  Geological  Survey,  Part  II,  page  57. 


362 


RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


be  1  to  388.  If,  on  this  basis,  all  the  sediment  carried  by  the  stream  be 
assumed  to  deposit  in  the  Elephant  Butte  reservoir,  it  would  catch  but  G50 
acre-feet  every  time  its  full  capacity  were  carried  through  it.  If  the  river 
carries  sutlicient  volume  to  fill  the  253,000  acre-feet  of  its  capacity  live 
times  per  annum  on  an  average,  it  would  require  130  years  to  fill  the 
reservoir.  Long  before  this  result  could  occur  it  would  be  profitable  to 
add  a  few  feet  to  the  height  of  the  dam,  or  construct  the  large  reservoir 
in  the  adjoining  basin  above,  or  take  measures  for  sluicing  out  a  portion  of 
the  accumulated  sediment.  It  does  not  appear  that  the  silt  problem  is  one 
which  need  give  serious  concern  in  this  situation. 

Evaporation. — The  loss  by  evaporation  from  the  surface  of  the  reser- 
voir is  estimated  by  the  chief  engineer  to  be  7  feet  in  depth  per  annum, 
based  on  the  observations  of  the  U.  S.  Geological  Survey  at  El  Paso  during 
1889-91.  From  this  he  computes  the  annual  loss  from  the  reservoir  at 
50,000  acre-feet,  and  from  the  surface  of  the  canals  at  22,000  acre-feet. 

Proposed  Reservoirs  in  Texas. — In  "Water-supply  and  Irrigation 
Papers,''  No.  13,  published  by  the  U.  S.  Geological  Survey,  Mr.  Wm.  F. 
Hutson  describes  some  large  projected  storage-reservoirs  on  the  Nueces 
Eiver,  in  Texas,  which  are  important  in  their  dimensions  and  of  general 
interest. 

The  Caimanche  Reservoir . — Caimanche  Lake  lies  to  one  side  of  the 
Nueces  Eiver,  and  gathers  the  water  of  a  large  drainage-basin  extending 
from  the  Eio  Grande  divide  on  the  south  to  many  miles  beyond  the  South- 
ern Pacific  Eailroad  on  the  north,  a  region  containing  springs  and  an 
easily  obtainable  supply  of  artesian  water.  It  is  proposed  to  convert 
Caimanche  Lake  into  a  storage-reservoir  by  means  of  an  earthen  dam  If 
miles  in  length  and  20  or  25  feet  in  height.  It  will  store  about  132,750 
acre-feet  of  water  at  the  spillway-level.  In  addition  to  the  natural  drain- 
age-basin tributary  to  the  lake  it  is  proposed  to  turn  into  it  the  water  of 
the  Nueces  Eiver  by  a  short  canal,  If  miles  long,  from  a  point  called  Eock 
Falls. 

The  area  of  the  reservoir  will  be  about  10,000  acres.  The  promoters 
expect  to  irrigate  from  this  reservoir  about  50,000  acres  of  land. 

The  Nueces  Reservoir. — Some  45  miles  below  Eock  Falls,  on  Nueces 
Eiver,  a  masonry  dam  has  been  projected  across  the  river,  2600  feet  in 
length,  50  feet  in  height,  which  will  form  a  reservoir  of  12,700  acres  in 
area  and  impound  222,250  acre-feet. 

Lower  Reservoirs. — About  100  miles  further  down  the  Nueces,  at  the 
junction  of  Frio  Eiver  and  below,  surveys  have  been  made  by  private 
capital  for  an  enormous  system  of  storage-reservoirs  for  irrigation.  These 
are  fourteen  in  number,  having  a  combined  storage  capacity  of  1,792,300 
acre-feet.  The  two  largest  of  these  will  be  formed  by  masonry  dams 
across  the  Nueces  and  Frio  rivers.    The  total  area  to  be  brought  under 


PROJECTED  BESEBVOmS. 


363 


irrigation  by  the  system  of  canals  to  be  supplied  by  these  reservoirs  is 
something  over  1,000,000  acres. 

Sand  Lake  Reservoir,  Western  Texas. — ^About  9  miles  north  of  Pecos 
City,  Texas,  a  natural  basin,  called  Sand  Lake,  has  been  selected  as  an 
available  reservoir-site  for  impounding  water  to  be  used  for  irrigating 
lands  in  the  vicinity  of  Pecos  City  and  Barstow.  The  basin  now  contains 
a  pond  of  300  acres,  maintained  by  the  run-off  from  the  local  watershed. 
The  basin  can  be  filled  to  a  depth  of  28  feet  before  overflowing,  impound- 
ing 55,000  acre-feet  and  covering  a  surface  area  of  374:0  acres.  A  dam 
on  the  rim  of  the  basin,  12  feet  in  maximum  height,  4000  feet  long,  would 
increase  the  area  to  5080  acres,  and  the  storage  capacity  to  79,200  acre- 
feet.  The  outlet  to  the  reservoir  would  require  a  cut  3  miles  long,  18  feet 
deep,  to  draw  off  72,500  acre-feet.  The  reservoir  would  be  fed  by  a  canal 
from  the  Pecos  Eiver,  23  miles  long,  having  a  capacity  of  450  second-feet, 
from  which  the  reservoir  could  be  filled  in  ninety  days.  The  total  cost  of 
the  canal  and  reservoir-outlet  is  estimated  at  $130,000. 

Upper  Pecos  Reservoir-site. — Some  50  miles  above  the  town  of  Eoswell, 
N.  M.,  a  notable  reservoir-site  exists  on  the  Pecos  Eiver,  where  a  dam  50 
feet  high  would  impound  250,000  acre-feet  of  water,  forming  a  lake  12 
miles  long,  2  miles  wide.  The  dam-site  is  at  a  point  where  the  river  has 
cut  through  a  ledge  of  limestone  to  a  depth  of  58  feet  on  the  west  side  and 
75  feet  on  the  east.  The  cost  of  a  masonry  dam  at  this  site  would  be 
about  $300,000,  or  $2.20  per  acre-foot  of  storage  capacity.  A  rock-fill 
and  earth  dam,  of  the  type  described  in  a  previous  chapter  as  having  been 
built  lower  down  on  the  Pecos,  would  be  about  one-half  the  cost  of  a 
masonry  dam. 

The  area  of  arable,  irrigable  land  in  the  valley  of  the  Pecos  between 
Eoswell,  N.  M.,  and  Grand  Falls,  Texas,  is  as  follows: 

Land  commanded  by  the  Pecos  Irrigation  and  Improvement 


Co.'s  canals  and  reservoirs  .  .  174,000  acres 

Land  between  State  line  and  Eiverton,  Texas   15,000 

Land  under  the  unfinished  Mentone  Canal,  east  side   36,000  " 

Land  under  the  Highland  Canal,  west  side   50,000  " 

Land  urder  the  Pioneer  Canal,  constructed   38,000  " 

Land  under  the  Pioneer  Canal,  extension   15,500  " 

Additional  area  below  Barstow   1,500  " 


Total   ..  330,000 


The  volume  of  water  annually  passing  the  head-gates  of  the  Pioneer 
Canal  at  Barstow,  as  determined  from  records  kept  for  several  years,  is 
approximately  700,000  to  1,000,000  acre-feet.    This  volume  is  sufficient 


30G         llESERVOTRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 

for  the  irrj<^-ation  of  all  the  lands  of  the  valley  if  properly  stored  and 
utilized. 

The  data  concerning  reservoir-sites  on  the  Pecos  River  are  taken  from 
a  report  hy  the  writer  made  in  1898. 

Rock  Creek  Reservoir,  Nevada. — One  of  the  tributaries  of  Humboldt 
River,  which  enters  that  stream  a  few  miles  above  Battle  Mountain,  Nevada, 
from  the  north,  is  known  as  Rock  Creek.  It  drains  a  watershed  of  750 
square  miles,  whose  altitude  ranges  from  5000  to  13,000  feet  above  tide- 
level.  As  it  debouches  into  Humboldt  Valley  it  passes  through  a  narrow 
gorge,  5  miles  long,  cut  deeply  through  a  volcanic  range  of  hills,  at  the 
head  of  which  is  a  favorable  site  for  a  dam  and  reservoir,  as  the  stream 
passes  through  a  large  open  valley.  The  capacity  of  this  reservoir  at  the 
75-foot  contour  above  the  base  of  the  dam  is  80,000  acre-feet,  covering 
3670  acres  (Fig.  171).    The  canyon  at  the  dam-site  is  but  120  feet  wide 


Fig.  173. — Sketch  of  Longitudinal  Section  of  Lost  Canyon  Natural  Dam 

at  bottom  and  but  300  feet  at  the  75-foot  level.  On  the  left  bank  the 
canyon  wall  rises  abruptly  to  a  height  of  over  250  feet  (Fig.  172).  The 
material  is  a  hard  porphyry  at  the  dam-site,  capped  at  a  few  hundred  feet 
height  by  a  layer  of  basalt  of  great  depth.  The  character  of  dam  proposed 
for  the  site  is  a  rock-fill,  of  the  Pecos  type,  faced  with  an  embankment  of 
earth.    The  estimated  cost  of  the  dam  is  about  $80,000. 

The  run-off  from  the  watershed  is  estimated  to  exceed  150,000  acre- 
feet  per  annum,  or  about  200  acre-feet  per  square  mile.  The  precipita- 
tion on  the  shed  varies  from  7  inches  annually  at  the  dam,  to  over  40  inches 
in  the  higher  mountain-ranges. 

Used  as  a  needed  supplement  to  the  normal  summer  flow  of  the 
Hamboldt,  the  reservoir  is  expected  to  irrigate  about  100,000  acres  of  the 
valley  lands,  bordering  the  river,  between  Battle  Mountain  and  Golconda. 


PR  0JEC2  ED  RES  ER  VOIRS. 


367 


Lost  Canyon  Natural  Dam,  Colorado.— The  region  of  Lost  Park  and 
Lost  Canyon,  on  Goose  Creek,  Colorado,  a  tributary  of  South  Platte  Elver, 
is  one  of  rugged  grandeur,  characterized  by  scenery  of  the  wildest  imagin- 
able description,  abounding  in  high  clif s  and  rock-masses  of  fantastic 
shapes  and  colors  and  of  Titanic  dimensions.  Nature  has  here  made  an 
effort  at  rock-fill  dam-construction  on  a  grand  scale  by  filling  in  the 
canyon  to  a  maximum  depth  of  250  feet  with  an  aggregation  of  enormous 
Taowlders  thrown  from  the  neighboring  cliffs.   This  remarkable  rock-fill  is 


Fig.  174.— Sketch  of  Cross-sbctton  at  Upper  End  of  Lost  Canyon  Natural  Dam. 


2100  feet  in  length,  and  is  fairly  well  represented  in  a  general  way  by  the 
longitudinal  and  cross  sections  shown  in  Figs.  173  and  174.  The  maximum 
height  above  the  upper  toe  is,  as  stated,  250  feet;  but  as  the  bed  of  the 
canyon  falls  150  feet  in  the  length  of  the  dam,  the  height  of  the  crest  is 
400  feet  above  the  lower  toe,  where  the  stream  emerges  from  underneath 
the  bowlders.  The  extreme  width  on  top  is  400  feet,  although  the  bulk, 
of  the  fill  is  less  than  100  feet  in  width,  and  at  the  bottom  the  canyon  width 


368        RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETO. 

between  well-polished  walls  is  but  20  to  25  feet,  at  such  places  as  it  is  pos- 
sible to  go  underneath  and  inspect  it. 

Some  of  the  bowlders  that  form  the  embankment  are  as  large  as  an 
ordinary  two-story  dwelling-house,  and  the  stream  finds  its  way  through 
them  with  little  apparent  obstruction,  although  the  presence  of  a  pile  of 
driftwood  at  the  mouth  of  a  cave  on  the  upper  face,  150  feet  above  the 
bottom,  is  an  indication  that  occasionally  the  volume  is  too  great  to  find 
exit  in  the  lower  passages  and  is  forced  to  rise  to  this  higher  outlet.  It  is- 
possible  to  descend  in  this  cave,  by  means  of  ladders  and  ropes,  into  the 
interior  of  the  dam  almost  to  the  water-level.  The  crest  of  the  solid  mass- 
of  the  dam  proper  is  at  the  200-foot  level,  although  a  chain  of  huge 
bowlders,  25  to  50  feet  high,  lying  near  together,  extends  across  the  canyon 
from  side  to  side.  The  entire  gurface  of  the  natural  embankment  is  dotted 
over  with  large  fir-trees,  growing  in  the  soil  that  has  lodged  in  the  crevices. 
As  the  stream  emerges  from  the  foot  of  the  dam  it  has  the  appearance  of 
a  spring  flowing  out  from  beneath  an  old  glacial  moraine. 

Surveys  of  the  site  have  developed  the  fact  that  a  reservoir  with  a 
capacity  of  24,000  acre-feet  can  be  made  available  for  storage  and  use  by 
making  nature's  dam  water-tight.  This  may  readily  be  done  by  filling 
the  crevices  and  cavities  on  the  upper  face  with  concrete  and  providing  a 
proper  outlet  for  the  water  by  means  of  a  tunnel. 

The  latter  has  been  projected  on  the  75-foot  level,  and  will  require  ta 
be  1200  feet  long  to  reach  a  neighboring  canyon.  The  cost  of  this  work 
has  been  estimated  at  $104,000,  or  $4.35  per  acre-foot  of  storage  capacity 
in  the  reservoir.  An  addition  of  20  feet  to  the  top  of  the  dam  would 
increase  this  capacity  to  27,700  acre-feet,  and  the  cost  to  $144,000,  the 
work  to  be  done  in  Portland-cement  masonry.  The  reservoir  has  been  in 
contemplation  for  some  years  as  a  storage  for  irrigation  and  domestic 
supply  in  and  around  Denver,  from  which  city  it  is  some  sixty  miles 
distant. 

California  Reservoir  Projects. — Little  Bear  Valley  Dam. — The  Arrow- 
head Reservoir  Company  of  Cincinnati,  whose  headquarters  are  located 
at  San  Bernardino,  Cal.,  began  construction  some  years  ago  on  a  masonry 
dam  of  large  proportions  which  is  to  store  water  in  a  mountain  valley, 
called  the  "  Little  Bear,'^  on  the  head  waters  of  the  Mojave  River.  This 
stream  flows  northward  into  the  Mojave  Desert,  and  its  water  runs  to 
waste.  The  project  of  the  Arrowhead  Company  is  to  gather  together  a 
number  of  the  tributaries  of  the  stream  above  an  elevation  of  4800  feet, 
store  the  water  in  reservoirs  and  convey  it  across  the  San  Bernardino 
Mountains  for  irrigation  in  the  San  Bernardino  Valley.  A  contour  map 
of  the  reservoir  is  shown  in  Fig.  175. 

The  dam,  of  which  a  portion  of  the  foundation  only  has  been  laid,  is 
designed  to  be  carried  to  an  extreme  height  of  175.5  feet  above  the 


PROJECTED  RESERVOIRS. 


369 


assumed  "  base of  the  dam,  although  the  lowest  foundations  will  be  20 
to  30  feet  lower  than  the  "base/'  The  outlet-tunnel  is  15.5  feet  above 
"  base."  The  dam  is  intended  to  be  a  monolithic  structure  of  Portland- 
cement  concrete,  arched  up-stream,  with  a  radius  of  550  feet  to  the  up- 
stream face.  Its  top  length  will  be  747  feet,  and  its  base  thickness  133 
feet. 

The  reservoir  will  cover  an  area  of  884  acres  and  impound  60,179  acre- 
feet  of  water. 

The  company  has  been  at  work  on  the  main  conduit  leading  from  the 
reservoir  since  1892,  their  efforts  being  directed  chiefly  to  the  opening  of 


Base  of  Dam 

Fig.  174(1. — Comparison  of  Dams  op  the  System  op  the  Arrowhead  Reservoir 
Co.  IN  the  San  Bernardino  Mountains,  California. 


the  principal  tunnels  on  the  line,  of  which  there  are  a  number.  The 
longest  of  these  is  the  outlet  to  the  reservoir,  4957  feet  in  length  exclusive 
of  approaches.  This  was  made  necessary  to  avoid  10  miles  of  canal  around 
a  long  mountain-ridge.  It  has  been  completely  lined  and  arched  with 
concrete.  Two  other  tunnels,  1844  and  1792  feet  long,  have  been  com- 
pleted, and  are  to  be  lined  during  the  summer  of  1900. 

The  total  length  of  conduit  required  to  turn  the  water  over  the 
summit  of  the  mountain-divide  is  13  miles.  From  the  summit  crossing 
to  the  grade  of  the  conduit  at  the  base  of  the  mountains  skirting  the 
upper  slopes  of  the  valley  north  of  San  Bernardino  the  total  descent  is 
2700  feet,  which  will  be  utilized  to  develop  power. 


370        BESERVOIES  FOR  IRRIQATION,  WATER-POWER,  ETC. 


The  voluiiie  of  water  which  the  company  expect  to  develop  and  supply 
is  5000  to  GOOO  miner's  inches  (100  to  120  second-feet)  of  continuous  How 
during  200  days  each  year. 

The  determination  of  the  volume  of  supply  which  can  be  impounded 
and  sold  from  the  system  has  been  the  result  of  eight  years  of  continuous 
stream  measurements  and  precipitation  records.  The  company  maintains 
26  rain-gauges,  located  at  different  points  on  their  watersheds,  and  a  large 
number  of  self-registering  devices  for  measuring  the  depth  of  overflow  on 
their  weirs.  It  is  doubtful  if  any  such  systematic  and  intelligent  study  of 
probable  available  water-supply  from  the  catchment  of  flood  run-off  prior 
to  the  construction  of  works  has  ever  before  been  attempted  in  the  West, 
and  the  final  result  must  prove  of  great  value  to  the  company,  as  well  as 
an  invaluable  addition  to  the  general  store  of  knowledge  on  such  subjects 
when  finally  made  public. 

The  area  of  the  watershed  directly  tributary  to  the  Little  Bear  Valley 
reservoir  is  but  6.6  square  miles,  but  it  will  be  fed  by  a  large  conduit 
diverting  the  water  from  Holcomb  Creek,  Deep  Greek,  and  intermediate 
streams.  This  conduit  will  consist  mainly  of  a  large  tunnel  from  Deep 
Creek.  The  entire  area  of  shed  from  which  the  system  will  be  supplied  is 
about  77  square  miles,  all  of  which  is  above  5000  feet  in  altitude,  on  a  well- 
forested  mountain-crest,  and  is  among  the  most  productive  areas  in  south- 
ern California  in  stream  run-off.  The  Little  Bear  Valley  drainage-basin 
shows  the  greatest  amount  of  precipitation  and  stream-flow,  and  in  the  period 
of  observation  has  given  a  minimum  of  600  and  a  maximum  of  2200  acre- 
feet  of  run-off  per  square  mile  per  annum.  An  intercepting-canal  13  miles 
in  length,  including  the  tunnel  mentioned  above,  to  gather  the  stream- 
flow  from  61.43  square  miles  of  watershed  lying  east  of  Little  Bear  Valley 
and  empty  it  into  the  main  reservoir,  is  an  essential  part  of  the  general 
system.  This  canal  will  have  a  capacity  af  200  to  400  second-feet,  increas- 
ing as  it  takes  in  each  successive  stream  on  its  way. 

Two  other  reservoirs  are  contemplated,  one  at  Grass  Valley,  4  miles  west 
of  Little  Bear,  elevation  5108  feet,  where  a  dam  175  feet  high  will  give 
27,547  acre-feet  of  capacity  on  a  reservoir  area  of  382  acres;  the  other 
at  Huston  Flat,  5  miles  west  of  Grass  Valley,  elevation  4450  feet.  The 
175-foot  contour  at  the  latter  site  will  give  a  capacity  below  it  of  24,753 
acre-feet.  This  dam,  being  near  the  line  of  the  conduit  from  Little  Bear 
reservoir,  which  would  pass  the  dam-site  at  an  elevation  of  nearly  300 
feet  above  the  175-foot  contour,  could  be  built  advantageously  by  the 
sluicing  and  hydraulic  jet  process,  as  an  abundance  of  material  for  the 
purpose  can  be  had  conveniently  on  both  sides  of  the  canyon  where  the 
dam  would  be  located.  To  utilize  this  reservoir  will  necessitate  a  tunnel- 
outlet  5900  feet  long,  and  it  has  been  proposed  to  make  this  tunnel  a  part 
of  the  main  conduit,  by  which  means  4J  miles  of  canal  would  be  saved,  the 


Fig.  n4b. — View  of  Huston  Flat  Resekvoir-site,  one  of  the  System  of  the 
Akkowhead  Reservoir  Co. 
This  clam  is  to  be  built  by  tlie  hydraulic-fill  process. 

371 


LIBRARV 
BNlVERSirVofiLLINOli 


Fig.  175.— Mai' 


All  Valley  Reseiivoiu. 


[7'o/ace  page 


OV  THE 


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PROJECTED  RESERVOIRS. 


373 


cost  of  which  would  be  about  60  per  cent  of  the  cost  of  the  tunnel.  These 
plans  are,  however,  somewhat  indeterminate.  The  cost  of  the  entire  sys- 
tem, not  including  the  Huston  Flat  reservoir  dam  and  outlet,  is  estimated 
in  round  numbers  at  $1,600,000. 

Projected  Reservoirs  in  San  Diego  County.— The  last  few  years  have 
iDeen  fruitful  in  the  projection  of  numerous  storage  enterprises  through- 
out the  arid  region  which  are  yet  awaiting  the  necessary  capital  for  their 
construction.  The  map  of  San  Diego  County  (Fig.  176)  shows  the  position 
of  a  number  of  capacious  and  favorable  sites. which  have  been  surveyed, 
in  addition  to  those  already  described,  for  storing  the  storm-water  of  that 
region.  The  topography  of  the  country  is  more  favorable  for  storing 
water  than  many  parts  of  the  State  better  supplied  with  permanent 
streams.   Cross-sections  of  several  of  these  sites  are  given  in  Fig.  177,  and 


Fig.  177.— Ciioss  section  of  Dam-sites  in  San  Diego  County,  California. 


tables  of  capacity  of  the  reservoirs  to  be  inclosed  by  them  will  be  found 
in  the  Appendix. 

The  Linda  Vista  Irrigation  District,  covering  an  area  of  44,000  acres, 
embracing  a  part  of  the  corporate  limits  of  San  Diego,  owns  the  Pamo, 
Santa  Maria,  and  Dye  Valley  sites,  and  has  projected  rock-fill  dams  for 
each  of  them.  The  Pamo  is  considered  most  favorable  for  immediate  con- 
struction, as  it  is  also  the  most  capacious. 

In  Riverside  County  a  masonry  dam  has  been  planned  to  span  a  narrow 
canyon  on  the  Pauba  Eancho  at  the  outlet  to  a  large  valley  on  Temecula 
Creek  which  drains  a  catchment-area  of  372  square  miles.  The  elevation  of 
ihe  dam  is  1350  feet  at  the  base,  and  it  commands  an  extensive  territory  of 
Taluable  agricultural  and  horticultural  lands.    The  dam  is  projected  to  a 


374         RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC. 


height  of  130  feet,  at  which  it  will  have  a  capacity  of  Gl,500  acre-feet, 
covering  1214  acres.  Its  cost  has  been  estimated  at  $400,000,  and  the  28 
miles  of  canals  for  distribution  to  40,000  acres  of  land  at  $230,000,  an 
average  cost  for  the  system  of  about  $16  per  acre. 

The  capacity  of  the  drainage-basin  for  run-off:  has  been  demonstrated 
in  a  striking  way  on  two  notable  occasions  when  floods  from  this  section 
destroyed  the  Southern  California  Eailway  through  the  Temecula  Canyon, 
causing  enormous  loss  and  destruction  of  property.  The  track  has  not 
been  restored  since  the  last  time  it  was  destroyed,  in  1890-91. 


Fig  178.— Map  of  Watershed  and  the  liANDS  to  be  itirigated  from  Victor 


Reservoir. 

Victor  Dam,  OaUfornia.—DouUless  the  most  capacious  reservoir  pro- 
jected in  California  is  that  of  the  Columbia  Colonization  Company,  located 
on  the  Mojave  Eiver  in  San  Bernardino  County,  at  the  Upper  Narrows, 
near  the  town  of  Victor  (Fig.  178)  on  the  line  of  the  Southern  California 
Eailway,  which  now  passes  through  the  site  of  the  dam,  and  will  have  to 
be  rebuilt  for  5^  miles  to  clear  the  reservoir.  The  pass  at  the  Narrows  is 
in  a  granite  ridge,  which  affords  most  admirable  buttresses  for  a  masonry 
dam,  and  is  a  remarkable  one,  favorable  in  all  respects  for  such  a  structure. 


PROJECTED  RESERVOIRS. 


375 


The  width  at  the  stream-bed  is  but  140  feet,  while  at  the  height  of  150' 
feet  the  walls  of  the  canyon  are  but  360  feet  apart.  Soundings  have  been 
taken  with  steel  rods  driven  through  the  sand,  which  show  the  maximum 
depth  to  what  is  believed  to  be  bed-rock  at  52  feet.  Fig.  179  is  a  cross- 
section  of  the  site,  showing  the  soundings,  and  Fig.  180  is  a  view  looking 


Fig.  179. — Cross- section  of  Victor  Dam-site. 

up-stream  from  the  county  bridge  through  the  dam-site,  the  stakes  shov/n 
in  the  water  marking  the  positions  of  the  various  soundings.  The  reser- 
voir-basin is  shown  in  Fig.  181,  and  Fig.  178  is  a  general  map  of  the 
watershed  and  the  lands  proposed  to  be  irrigated. 

As  planned,  the  dam  will  contain  about  70,000  cubic  yards  of  masonry. 


376         RESEEVOim  FOR  IRllIOATION,  WATER-POWER,  ETC. 


including  the  filling  of  a  narrow  gap  in  the  rim  rock  above  the  105-foot 
contour,  some  500  feet  west  of  the  dam  proper.  On  the  opposite  side 
a  natural  spillway  of  ample  dimensions  exists  at  a  height  of  145  feet,  by 
which  the  waste  will  be  returned  back  to  the  channel  at  a  safe  distance 
below  over  a  ledge  of  solid  granite.  The  reservoir  at  the  145-foot  contour 
covers  an  area  of  7718  acres,  and  has  a  capacity  estimated  at  17,000,000,000 
cubic  feet,  or  390,000  acre-feet,  the  mean  depth  being  50i  feet,  or  34.86 
per  cent  of  the  maximum.  The  ratio  between  mean  and  maximum  depth 
in  all  large  commodious  reservoir-basins  which  have  a  fairly  uniform  slope 
of  stream-bed  from  the  dam-site  up,  and  do  not  show  a  series  of  rapids 
for  a  distance  above  the  dam,  is  found  to  range  from  28  to  45  per  cent, 
and  it  is  often  customary  on  preliminary  estimates,  after  determining  the 
area  of  the  highest  contour  embracing  the  reservoir,  and  before  making 
detailed  survey  of  the  interior  of  the  basin,  to  apply  such  a  percentage 
of  the  height  of  the  dam  for  computation  of  contents  as  the  engineer  may 
consider  safe  within  these  limits,  taking  into  consideration  the  general 
topography  of  the  site.  Such  has  been  the  method  of  determining  the 
capacity  of  the  reservoir  in  question. 

The  watershed  area  draining  out  through  this  dam-site  is  somewhat 
indeterminate  from  lack  of  surveys  in  the  eastern  part,  but  it  has  been 
roughly  computed  as  1250  square  miles,  of  which  the  drainage  from  the 
greater  portion  of  77  square  miles  on  the  mountain-crest  may  be  diverted 
by  the  works  of  the  Arrowhead  Eeservoir  Company.  The  precipitation  has 
a  wide  range  of  variation,  from  60  inches  and  upward  on  the  summits  of 
the  mountains  to  5  or  6  inches  at  the  dam.  Measurements  made  by  F.  W. 
Skinner,  civil  engineer,  between  Januarv  1  and  August  1,  1893,  gave  a 
maximum  discharge  of  8500  second-feet  and  a  minimum  of  38  second-ieet, 
from  which  the  mean  flow  from  August  1,  1892,  to  August  1,  1893,  was 
computed  as  825  second-feet.  This  would  be  equivalent  to  an  annual 
run-off  of  597,300  acre-feet,  or  nearly  double  the  proposed  reservoir 
capacity.  At  the  same  time  it  was  noted,  by  the  appearance  of  the  drift 
along  the  banks  and  the  statements  of  the  residents  of  Victor,  that  the 
highest  floods  of  that  season  lacked  several  feet  of  reaching  the  high- 
water  marks  of  previous  years. 

In  connection  with  the  laying  of  the  foundations  of  the  dam,  it  is  in- 
teresting  to  consider  the  probable  volume  of  underflow  in  the  stream  at 
this  point.  The  area  of  cross-section  shown  by  the  soundings  below  the 
surface  is  approximately  4160  square  feet.  The  rate  of  percolation  deter- 
mined by  the  Agua  Fria  dam-construction  (p.  234),  if  applied  to  this  area, 
would  give  an  underflow  of  11  miner's  inches;  and  even  if  this  were  multi- 
plied by  10,  the  flow  to  be  handled  by  pumps  during  construction  would  be 
but  little  more  than  4  second-feet,  which  is  not  a  formidable  amount  to 
contemplate  taking  care  of. 


380 


EKSERVOmS  FOll  IRRIGATION,  WATER-POWER,  ETC. 


The  lands  to  be  irrigated  from  the  reservoir  lie  west  of  the  river,  be- 
tween the  Southern  California  Railway  and  the  Atlantic  and  Pacific  Rail- 
road, and  north  of  the  latter.  The  area  of  good  land  in  this  region  re- 
quiring water  is  greatly  in  excess  of  the  probable  water-supply.  The  cost 
of  the  entire  system  of  storage  and  distribution,  including  canals  and 
laterals  delivering  water  to  200,000  acres,  is  estimated  at  $1,742,000,  or 
$8.46  per  acre,  although  the  company  states  that  it  has  secured  bids  from 
reliable  contractors  which  will  greatly  reduce  these  figures  of  cost.  It 
appears  to  be  an  enterprise  which  would  reclaim  so  large  an  area  of  the 


Fig.  182.— Map  of  Manache  Meadows  Reservoir. 


public  domain  that  is  now  a  desert  as  to  entitle  it  to  be  classed  among 
those  which  should  be  carried  to  successful  completion. 

Since  the  above  article  was  written  in  1897,  the  U.  S.  Geological  Sur- 
vey has  made  borings,  in  1899,  to  determine  the  depth  to  bed-rock,  with 
the  diamond  drill-core,  and  practically  confirmed  the  correctness  of  the 
original  soundings. 

Projected  Reservoirs  on  Kern  River,  California. — A  number  of  available 


PROJECTED  RESERVOIRS. 


381 


sites  for  impounding  a  considerable  volume  of  the  flood-waters  of  Kern 
River  have  been  surveyed  in  the  mountains  near  the  sources  of  that  noble 
stream  the  "Rio  Bravo  of  the  South/'  as  it  was  known  to  the  native 


Fig.  183.— Map  of  Manache  Meadows  Dam- site. 


Californias,  the  largest  of  which  is  in  the  Manache  Meadows,  on  the 
south  fork  of  Kern  River,  at  an  elevation  of  8200  feet  above  sea-level  (Fig. 
182).   A  rock-fill  dam  at  this  site,  estimated  to  cost  $150,000,  will  create 


382 


RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC 


a  reservoir  of  5830  acres  and  impound  248,850  acre-feet,  from  which  it  is 
apparent  that  the  site  takes  front  rank  among  the  most  capacious  sites  that 
have  come  to  public  notice  in  the  West.  The  locality  has  the  appearance 
of  having  been  a  large  lake  in  a  comparatively  recent  geological  period, 
and  the  basin  is  so  fiat  that  it  is  classed,  and  has  been  surveyed  and 
segregated,  as  "  swamp  and  overflowed  land.'^ .  The  highest  peaks  in  the 
catchment-area  are  over  13,000  feet  high,  and  Mount  Whitney,  15,000  feet 
in  altitude,  is  drained  on  one  side  by  Whitney  Creek,  the  water  of  one 
branch  of  which  can  be  diverted  into  the  reservoir  by  an  inexpensive  cut. 
The  area  of  drainage  naturally  tributary  is  155  square  miles. 

The  dam-site  (Fig.  183)  shows  solid  ledges  of  granite  on  each  side,  and 
soundings  indicate  that  bed-rock  is  but  8  to  10  feet  below  the  surface 
across  the  canyon-bed,  which  is  but  160  feet  wide  at  the  bed  of  the  stream 
and  460  feet  wide  at  a  height  of  85  feet.  Lime  can  be  burned  for  use  on 
Whitney  Creek,  20  miles  distant,  and  there  is  a  great  abundance  of  timber 
which  clothes  all  the  surrounding  mountains. 

The  Manache  Meadows  reservoir-site  has  been  located  by  the  Kern- 
Eand  Eeservoir  and  Electric  Company  of  Los  Angeles,  with  the  view  of 
■utilizing  it  to  equalize  the  flow  of  the  stream  suflficiently  to  enable  them  to 
use  the  water  continuously  for  power.  The  fall  available  at  the  middle 
power-station  is  2250  feet,  which  it  is  proposed  to  utilize  in  one  drop,  gen- 
erating 24,000  H.P.  and  transmitting  it  electrically  to  Los  Angeles,  125 
miles  distant.  The  upper  station  has  an  available  drop  of  about  1900  feet, 
requiring  a  conduit  of  15  miles  to  reach  it.  The  lower  station  has  a  drop 
of  200  feet  and  would  deliver  water  to  the  highest  of  the  irrigation-canals 
in  South  Fork  Valley.  The  total  theoretical  power  available  for  all  three 
stations  is  estimated  at  45,870  H.P.,  of  which  about  30,000  H.P.  may  be 
delivered  to  points  of  intended  use. 

The.  mountain  valley  of  the  South  Fork,  above  its  junction  with  the 
North  Fork,  has  an  altitude  of  about  3600  feet,  and  contains  some  25,000 
acres  of  good  arable  land,  of  which  about  15,000  acres  are  irrigated,  chiefly 
for  alfalfa.  There  are  thirty  ditches,  each  from  IJ  to  3  miles  in  length, 
5  to  6  feet  wide  on  bottom,  and  carrying  1  to  2  feet  depth  of  water.  The 
reservoir  in  the  Manache  Meadows  would  interfere  with  the  supply  to  these 
ditches  only  during  the  last  half  of  July  and  the  months  of  August  and 
September.  During  the  remainder  of  the  year  the  streams  below  the 
Meadows  are  adequate  for  this  service.  In  fact,  the  Manache  is  but  one- 
fifth  the  total  area  of  the  South  Fork  drainage  above  the  South  Fork  farm- 
ing community,  and  probably  does  not  supply  more  than  40  per  cent  of  the 
flow  of  the  stream. 

The  main  characteristics  of  the  North  and  South  forks  of  Kern  Eiver 
are  as  widely  different  as  though  the  streams  were  in  separate  States.  The 
North  Fork  rises  in  very  high,  rugged,  and  precipitous  mountains  on  which 


PROJECTED  RESERVOIRS. 


383 


the  snow  lies  late  in  summer.  Its  canyon  is  a  deep,  narrow  gorge  through- 
out its  entire  length,  from  its  source  to  Kernville,  near  its  junction  with 
South  Fork,  with  only  here  and  there  a  narrow  strip  of  meadow-land  along 
the  stream,  not  in  any  way  resembling  the  expansive  meadows  and  open 
plains  which  characterize  the  South  Fork  for  so  great  a  part  of  its  course. 
The  North  Fork  drains  1069  and  the  South  Fork  754:  square  miles  of 
watershed,  but  the  precipitation  and  run-off  of  the  two  sheds  vary  so 
greatly  that  the  normal  flow  of  the  former  is  ten  to  twelve  times  greater 
than  the  latter  at  their  point  of  junction.  Unfortunately  the  relative 
advantages  of  the  two  forks  respecting  sites  for  storage  seem  to  be  m  in- 
verse ratio  to  their  volume  of  flow  and  capacity  for  filling  reservoirs. 

Kern  Lake  Reservoir.— One  of  a  large  number  of  sites  surveyed  in  1881 
by  the  State  Engineering  Department  of  California  is  at  the  "  lake  "  on 
North  Fork,  where  a  landslide  has  filled  the  canyon  some  20  feet  and 
created  a  pond  40  acres  in  area.   This  place  has  been  viewed  with  the  idea 
of  constructing  a  high  rock-fill  dam,  to  be  formed  by  a  few  huge  blasts  from 
the  cliffs  that  tower  almost  vertically  above  it  for  2000  to  3000  feet.  The 
capacity  of  a  reservoir  at  this  place  would  be  46,600  acre-feet  at  the  220- 
foot  level,  covering  about  600  acres.   The  outlet  would  be  made  by  means 
of  a  tunnel  of  sufficient  capacity  to  carry  the  river  during  construction  of 
'the  dam.   The  plan  suggested  contemplates  filling  the  canyon  for  several 
hundred  feet  with  such  an  enormous  mass  of  rock  as  to  give  it  unques- 
tionable stability,  and  after  it  is  thrown  down,  to  lay  up  a  dry  wall  on  its 
upper  face  and  cover  it  with  asphalt  concrete,  excavating  a  spillway  en- 
tirely around  the  dam  so  created.   The  canyon  width  at  the  site  is  but  100 
feet  at  bottom  and  400  feet  at  a  height  of  230  feet.   The  work  is  estimated 
to  cost  $225,000.  , 
One  of  the  advantages  of  the  reservoir  in  this  locality  would  be  that 
it  could  be  filled  twice  a  year  or  oftener.    Experience  has  demonstrated 
that  the  usual  shortage  in  supply  to  the  Kern  Valley  canals  occurs  twice 
a  year— in  February  and  March,  and  in  August  and  September.   In  these 
'    months  a  reinforcement  of  the  stream  is  very  much  needed.   Between  each 
of  these  periods  the  North  Fork  reservoir  could  be  filled  and  its  contents 
made  available  for  the  next  low  stage. 

It  may  be  considered,  therefore,  that  the  reservoir,  if  built  and  oper- 
ated in  the  manner  suggested,  would  practically  add  46,000  acres  to  the 
irrigable  area  of  the  valley,  at  a  cost  of  about  $5  per  acre. 

Big  Meadows  Reservoir.— Located  on  Salmon  Creek,  a  branch  of  the 
North  Fork  of  Kern  Eiver,  at  a  point  known  as  Big  Meadows,  is  a  site 
where  a  dam  of  75  feet  height  will  form  a  reservoir  of  870  acres  that 
would  impound  31,150  acre-feet  of  water.  The  dam-site  is  in  a  granite 
canyon  with  clean  bed-rock  on  bottom  and  sides,  the  width  at  bottom  be- 
tween walls  being  but  25  feet,  while  the  top  width  at  the  75-foot  level 


384        RESERVOIRS  FOR  IRRIGATION,  WATER-POWER,  ETC, 


would  be  390  feet.  A  rock-fill  dam  is  estimated  to  require  26,000  cubic 
yards  of  material,  and  to  cost  $80,000.  The  area  of  watershed  is  estimated 
at  14  to  25  square  miles. 

Throughout  the  higher  Sierra  Nevada  are  innumerable  lakes  of  con- 
siderable area  and  capacity,  generally  so  high  as  to  be  above  the  timber- 
line,  which  can  be  utilized  as  storage-reservoirs  at  small  expense.  They 
may  be  counted  by  the  hundreds  on  the  headwaters  of  Kings,  San  Joaquin, 
Merced,  and  Tuolumne  rivers,  although  it  cannot  be  said  that  any  of  them 
are  so  extensive  or  capacious  as  to  be  distinctly  noticeable  or  require  special 
description.  Preparations  are  being  made  by  people  living  in  Visalia  to 
utilize  two  such  lakes  on  the  headwaters  of  the  Kaweah  River  in  a  some- 
what novel  manner.  By  means  of  a  number  of  10-inch  pipes  they  propose 
to  siphon  the  water  out  of  the  lakes  to  a  depth  of  about  20  feet,  and  as 
one  of  them,  called  Moose  Lake,  is  about  300  acres  in  area,  it  is  expected 
to  draw  from  it  in  the  season  of  greatest  shortage  about  5000  to  6000  acre- 
feet  of  water.  The  other,  known  as  "  Big  Lake,"  has  almost  as  large  an 
area.  This  method  of  utilizing  the  lakes  without  the  expense  of  building 
dams  may  have  more  than  a  local  application. 

On  the  eastern  slope  of  the  Sierra,  near  the  town  of  Independence,  a 
high  mountain  lake  of  this  sort  has  been  tapped  by  a  cut  about  10  feet 
in  depth,  which  has  given  a  flow,  as  reported,  of  several  hundred  inches 
more  than  customarily  came  from  it  before. 

ACKNOWLEDGMENTS. 

Throughout  the  text  of  this  work  the  author  has  endeavored  to  make 
due  acknowledgment  for  information  furnished  and  courtesies  extended, 
in  connection  with  each  of  the  subjects  treated.  If  any  omissions  have 
been  made,  their  subsequent  discovery  will  cause  him  sincere  regret  and 
mortification.  To  cover  any  such  omissions  in  the  first  edition  he  begs 
to  make  a  broad  and  general  expression  of  gratitude  for  all  aid  extended 
in  making  the  work  more  complete. 

Special  acknowledgments  are  due  the  Director  of  the  U.  S.  Geological 
Survey,  and  to  Mr.  F.  H.  Newell,  Chief  Hydrographer,  for  the  use  of  the 
greater  portion  of  the  cuts  and  illustrations  which  embellish  the  fore- 
going pages,  and  are  indispensable  to  the  proper  understanding  of  the  text. 


APPENDIX. 


CONTAmiNG  TABULATED  DATA  OF  EESERVOIR  SURVEYS 
MADE  BY  THE  U.  S.  GOVERNMENT;  TABLES  SHOW- 
ING THE  COST  OF  RESERVOIR  CONSTRUCTION 
PER  ACRE-FOOT  IN  THE  UNITED  STATES 
AND   IN   FOREIGN  COUNTRIES,  AND 
TABLES  OF  RESERVOIR  CAPACI- 
TIES AND  AREAS. 


386 


APPENDIX. 


V.  S.  Kesekvoik  Sukveys  in  California. 


Tiocation, 


Clear  Lake  

Independence  Lake 
Webber  Lake  

Donner  Lake  


Soda  Springs   ... 

Truckee  River  

Little  Yosemite  Valley 
Lake  Tenaya  


Tuolumne  Meadows. 

Lake  Eleanor  

Kennedy's  Meadows. 
Kennedy's  Lake  . . . 


Blood's  Creek. 


Red  Lake  

Pleasant  Valley  ....  . . . . 

East  Carson  Creek  

Indian  Pool,  Deer  Creek. 

Heenan  Lake  

Silver  King  Valley  

Wolf  Creek  

Dumont's  Meadows  

Mokelarane  River. ...... 


Pacific  Valley   

Bell'sMeadows,  CanyonCr 
Coffin's  Hollow,     "  " 

Hull's  Meadows  

Granite  Lake  

Cherry  Valley  

Lake  Vernon  

Big  Meadows.  

Errarar's  Meadows  

Hetcli-Hetchy  Valley  

Little  Truckee  River  .... 

Stampede  Valley.  

Twin  Valley  

Little  Trucikee  River. .  .  . 

Monument  Peak  

Young's  Crossing  

Grass  Lake  

Hope  Valley  

Harvey's  Meadows  

American  River  

Twin  Lakes  

U.  S 

Truckee  River,  lower. 
"  "  upper. 

Long  Valley  Creek .... 

West  Carson  River  


Altitude 
Feet. 


5,808 
6,997 
6,769 

6,095 

6,750 
6,190 
5,980 
7,990 

8,339 

4,561 
6,182 
8,009 

6,911 

7,850 
5,900 
6,000 
8,000 
7,100 
6,400 
6,500 
7,500 
7,020 
6,840 
7,000 
5,500 
5,000 
5,000 
5,040 
4,500 
6,530 
7,500 
5,000 
1,500 
6,430 
5>00 
6,200 
5,550 
7,700 
5,200 
7,800 
7,050 
5,900 
7,800 
7,900 


Water- 

Reser- 

shed 

voir 

Area. 

Area. 

Sq.  Mi. 

Aci-es. 

413 

40,821 

984 

778 

1,337 

 \ 

2,006 

6 

300 

12 

225 

132.5 

862 

11 

597 

169 

48 
67.5 
5.4 

4.7 

Small 


Small 


Extens. 


Small 


Small 


410 


12 
Ample 


Small 
Ample 
Small 


1,081 

1,127 
128 
110 

348 

80 
60 
40 
20 
130 
255 
190 
225 
75 
30 
75 
280 
175 
115 
220 
165 
480 
980 
95 
680 
450 
120 
310 
350 
160 
150 
350 
1,808 
40 
135 
420 


Reser- 
voir 

Cair)ac- 
ity. 

Acre-ft. 


Reservoir  Surveys  in 


4,250 
4,300 


7,050 


1,000 
1,000 


400 
395 

1,086 

1,800 


385,300 
23,707 
11,152 
22,205 
42,827 
2,400 
1,350 
45,195 
23,000 

43,185 

45,770 
7,408 
2,000 

6,917 

1,050 
790 
975 
160 
1,460 
5,740 
4,630 
5,480 
1,120 
430 
980 
6,300 
2,200 
2,160 
3,300 
2,500 
5,700 
11,000 
1,070 
25,500 
10,100 
2,250 
3,480 
6,500 
4,800 
3,370 
4,000 
90,810 
600 
2,400 
4,700 
Nevada 
7,500 
7,400 

34,425 
90,810 


Area 

Set!:re- 
galed. 

Acres. 


)0,921 


680 
560 
1,694 
1,400 

1,880 

1,910 
360 
440 

881 

860 
402 
200 
25 
400 
722 
600 
680 
320 
200 
320 
800 
480 
379 
520 
720 
920 
400 
312 
1,440 
1,043 
440 
840 
880 
433 
640 
920 
2,953 
280 
440 
884 

1,000 
1,040 


Height 

of 
Daui. 

Feet. 


None 
40 
30 
26 
18 
20 
16 
115 
35 

r  75 

I  18 
j  45 
t  65 
65 
102 
31 
55 
20 
15 
35 
85 
65 
23 
80 
60 
65 
65 
40 
88 
35 
60 
85 
50 
40 
40 
30 
30 
80 
100 
60 
50 
30 
50 
80 
60 
30 
163 
40 
47 
80 


63 
50 
\  60 
\  100 
163 


Length 
of 
Dam. 

Feet. 


None 
1,828 
812 
8,021 


530 
915 
1.075 
870 


1,300 
410 
900 

1,670 
300 
240 


450 
400 
530 
344 
660 
425 
315 
344 
317 
1,200 
770 
555 
290 
530 
660 
320 
800 
320 
318 
370 
530 
400 

* '  525 

1,500 


1.000 
870 


APPENDIX. 


387 


U.  S.  Reservoir  Surveys  in  Colorado 


4 
5 
6 
7 

8 

9 
10 
11 

12 

13 

14 

15 

16 

17 

18 

19 

20 

21 

22 

23 

24 

25 

26 

27 

28 

29 

80 

31 

32 

33 
34 
35 
36 
37 
38 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 
53 
54 
55 


Location, 


Twin  Lakes,  Arkansas  R. 
Leadville,  "  " 

Clear  Creek  


Hayden  

Sugar  Loaf  

Seven-Mile  Creek. . . 
Tennessee  Park. . . . 
Wet  Mt.  Valley. . . . 

Pine  Creek  

Slate  Creek  , . . .  . 

West  Oil  Creek  

Oil  Creek  

West  Beaver  Creek . 

Beaver  Creek  

Oil  Creek   

Wilson  Creek  

Sand  Creek  

Six-Mile  Creek  

Eight-Mile  Creek, . . 

Beaver  Creek  

Turkey  Creek  


Altitude. 


Feet. 


9  194 
10,000 


Water- 
shed 
Area. 

Acres. 


587 


Arkansas,  8  ra.  ab.  Pueblo 

Rush  Creek  

Cottonwood  Lake  

St.  Charles  River  


Graneros  Creek, . . 
Huerfano  River.  . 
Cucharas  River. . . 
Arapahoe  Creeic .  . 
Santa  Clara  River. 
Apishapa  River  .  . 
Purgatoire  River.  . 
Stonewall  Valley, , 


9,240 
10,000 
8,400 
9,870 
8,000 
7,900 
8,100 
8,500 
8,500 
9,000 
9,000 
5,800 
5.900 
5,450 
5,500 
5,500 
5,100 
5,400 
5.(i00 
4.840 
5,400 


30 


ILeser- 
voir 
Capac- 
ity, 

Acres.    Af^re  ft. 


3.475 


Apishapa  River  

Monument  Creek  

Smith  Canyon  Creek. . . 

Rule  Creek  

Cottonwood  Creek  

Two  Butte  Creek  

Nat.  Basin,  n.  Rocky  Ford 

"       "     "  La  Junta. 

"  "  "  Arlington, 
Arkansas  River  


Pine  Creek,  n.  Arkansas. 


Arkansas  River. . . 

Oak  Grove  

Rock  Creek  

Timpas  Creek  

Las  Animas  River, 


4,980 
6.300 
5,892 
6,895 
7,800 
7,200 
6,700 
6.850 
6,620 
8,300 
8,200 
5,600 
6,950 
4,700 
4  250 
4,300 
4,500 
4,250 
4,150 
4,150 
10,600 
10,100 
8,600 
8,545 
8,000 
6,425 
5,200 
4,950 
4,450 


160 


Ar^a 

Wegre- 

gaied. 


103,500 
8,875 

7,000 

45,000 
45,0C() 
4,550 
37,000 
119,100 
1,520 
8,570 
2,250 
56,200 
28,450 
620 
4,800 
2,900 

I,  950 
3,100 
4,550 
7,100 
9,800 
1,920 

359,000 
2,100 
8,400 
2,640 
3,340 
27.200 

I,  960 
4,125 

13,300 
10,150 
12,790 
6,200 

II,  200 
22,700 

3,840 
5,630 
34,280 
32,780 
25,680 
5,900 
14,720! 
21,407 
43,300 
9,600 
4,100 
1,500 
2,500 

II.  940 
1,310 
6,600 

13,640 
43,330 


Heiglit 

of 
Dain, 

Feet. 


4,716 
760 

720 

2,292 
1,915 
560 
2,396 
3,636 
334 
1,294 
640 
2,731 
2,400 
160 
480 
481 
360 
320 
520 
516 
1,000 
356 
3,643 
680 
686 
440 
660 
1,406 
400 
4(0 
1,040 
1,240 
920 
956 
222 


720 
480 
3,003 
2,860 
1,806 
1,000 
1,234 
2,420 
5,922 
714 
600 
240 
319 
1,202 
960 
960 
1,520 
4,040 


73 

l(;5 
65 
80 

1'20 
50 

100 
68 

140 

100 
86 
67 

159 
96 
63 

100 
90 
84 

100 
70 


Length 

of 
Dam. 

Feet. 


80 
60 
90 
50 
110 
27 
77 
165 
49 
132 
139 
142 
115 
120 
135 
142 
31 
47 
98 
83 
58 
50 
20 
none 

50 
45 
70 
60 

120 
84 
70 
88 

108 


3.650 
1,162 
1,560 
725 
1.445 
1,800 

825 


1,268 


1,160 
3,009 


388 


APPENDIX. 


U.     S.  liESKIlVOIIl  SI]Il^'EYS  IN  MOISTAKA. 


Location 


Sun  IJiver 


Altitude. 


"       "    ,  North  Fork.. .  i 
"       "    .South  Fork. 
Willow  Creek   


Sun  River. 


Benton  Lake  

Near  Martin sdale . 


Daisy  Dean  Creek. . 


N.  Fork,  Musselshell  II... 
S       "  "  "... 


Sixteen-Mile  Creek. . . 
S.  Fork,  Smith  River. 


Confederate  Gulch, 


Mitchell  Creek  

Big  Hole  River  

Black-tail  Deer  Creek . . . 

Beaver  Head  River  

Red  Rock  River  

Ruby  River  

Nat.  Basin.  Choteau  Co. 


Box  Elder  Creek  

West  Otter  Creek... . 

Sage  Creek  

Judith  River  

Dry  Basin  near  Ut'ca. 

it  n  << 

Lebo  Lake  

Near  Martinsdale  


8,633 
5,015 
4,900 
5.000 
4,830 
5,435 
5,000 
5,100 
5.550 
5.625 
5,330 
4,000 


5,000 
6,000 
5.500 


5,300 


3.600 
5,000 
4,900 
5,000 
4  900 
4,900 
5.000 
6,000 


Water- 
shed 
Area. 

Sq.  Mi. 


1,172 

1,136 
668 
318 
87 

37 

small 


10 


85 


25 
120 


Reser- 
voir 
Aiea. 


275 

367 
1,103 

570 
1,560 

340 

285 
140 
70 
9,130 
80 
40 
20 
30 
40 
100 
25 
1,055 
120 
110 
15 

50 
11,800 
600 
1,400 
1,200 
400 
3,800 
200 
180 
70 
30 
100 
35 
55 


250 


Reser- 
voir 

Capac- 
ity. 

Acie-ft. 


5,249 

13,013 
50,056 
19,591 
86,605 

6,081 

5.226 
2,091 
727 
140,200 
160 
800 
105 
890 
520 


19,781 
1,125 
1.230 


3.000 
1,500 
250 
3,000 
200 
350 


Area 
t;ated. 


1,014 

1,240 
1,760 
1,080 
2,360 

1,120 

880 
440 
;i60 
11,937 
210 
120 
160 
200 
240 
320 
120 
2,279 
440 
860 


240 
10,705 
1,155 
2,640 
1,894 
920 
3,944 
520 
960 
360 
160 
360 
160 
160 
676 
649 


Heitrht 

of 
Dam. 

Feet. 


I  15 
I  57 
'  99 
122 
113 
84 
15 
74 
41 
23 
35 


15 
40 
15 
35 
85 
55 
20 
50 
25 
30 
10 

15 
100 
40 
125 
40 
35 
20 
15 
46 
66 
21 
76 


Length 
of 
Dani. 

F<^et. 

630 
590 
380 
470 
677 
573 
855 
690 
8,160 
523 
481 


U.  S.  Reservoir  Surveys  in  Utah. 


1  Bear  Lake,  partly  in  Idahr 

2  Silver  Lake  

8  Twin  Lakes  

4  Mary's  Lake  

5  Sevier  River,  near  Oasis., 

6  Sanpitch  River  

7  Sevier  River  


5  949 

2,400 

69,120 

208,000 

6,014 

8 

55 

8,734 

3 

140 

2,500 

440 

53 

5,200 

f 

25 

450 

160 

20 

180 

9,000 

a 

25 

550 

160 

35 

140 

4,H00 

5.000 

940 

10,000 

2,878 

16 

475 

5,100 

500 

880 

9,000 

2,001 

22 

580 

5,700 

2,510 

290 

1,600 

920 

10 

250 

APPENDIX. 


389 


U.  S.  Reservoir  Sur\eys  in  Utah. 


Location. 


1 

2 
3 
4 
5 
6 
7 
8 
9 

10 
11 
13 

13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
■27 
28 
29 
30 
31 
32 
33 

34 

35 
36 
37 
38 
39 


East  Fork,  Sevier  River. 

Otter  Creek  

East  Fork,  Sevier  River. 


Panquitcli  Lake, 
Blue  Spring-.. . . 


Altitude. 

Water- 
shed 
Area. 

Reser- 
voir 
Area. 

Reser- 
voir 
Capacity. 

Area 
Segre- 
gated. 

Height 

of 
Dain. 

Length 

of 
Dam. 

Feet. 

Sq.  Mi. 

Acres. 

Acre-ft. 

Acres. 

Feet. 

Feet. 

6,200 
6,200 
7,000 
7,200 
8,100 
8,200 

700 
500 
575 
300 
80 
25 

460 
1,860 
3,050 

770 
1,280 

440 

3,000 
14,000 
76,000 

3,500 
10,700 
13,000 

1,120 
3,360 
4,956 
1,278 
1,560 
845 

12.5 
15 
50 
10 
10 
48 

280 
200 
2'25 
6,325 
110 
250 

U.  S.  Reservoir  Surveys  in  New  Mexico. 
 I 


Horse  Lake  

Bowlder  Lake   7,r,00 

Stinking  Lake   7  500 

Vallecitos  Creek   7,000 

Near  El  Rito   7,000 

Vallecitos  Creek    7,000 

RioCaliente   7,000 

Rio  Hondo. . 
Rio  Colorado 

RioPicuris   7,000 

Rio  Picuris  and  Rio  Lusio 

Rio  Grande   6.000 

Rio  Jemez,  East  Fork. 

9,000 
8,500 
8.400 


Rio  Salado  

Rio  Jemez  

Santa  Fe  Creek  

Rio  Medio  and  Rio  Frijole 
Rio  Mora  


Manuelitos  Creek .... 

Cherry  Valley  Luke. 
Rio  Gallinas  ...  . . . 

Rio  Pecos  


Rio  Grande  

Rio  San  Jose  

San  Mateo  Creek  , 
Blue  Water  Creek. 


7.000 


8,000 
7,000 


6,000 
6,000 


6,000 
6.000 


Agua  Fria  Creek. 


Rio  Colorado, 
Rio  Salado. .  . 
Rio  Alamosa 
Rio  Grande. . 


1,120 

21,000 

Unsg.? 

40 

2',  2  50 

51,000 

100 

3^630 

125,000 

50 

100 

3,500 

100 

60 

3,000 

200 

150 

60 

1,800 

60 

80 

330 

10^000 

1,059 

80 

50 

1,000 

100 

270 

9',  000 

100 

62 

1,200 

62' 

60 

236 

6,000 

236 

80 

1,500 

30,000 

1,500 

50 

4',  030 

18,000 

256 

5,000 

256 

53.5 

212 

4,500 

212 

57 

575 

13,000 

58 

1.046 

32,000 

1,046 

70 

155 

3,700 

155 

60 

1,640 

60,000 

1,640 

90 

40 

1,100 

200 

72 

45 

800 

45 

5t) 

620 

5,400 

620 

60 

1,770 

38,000 

1,770 

90 

1,037 

41,000 

1,037 

100 

800 

15,000 

1,400 

none 

170 

5.800 

170 

100 

370 

8,800 

370 

75 

250 

7,800 

82 

4,452 

87.000 

198 

31 

900 

20,000 

900 

46 

380 

5,500 

880 

43.5 

490 

3,000 

960 

19 

1,900 

53,000 

3,540 

74.5 

i  21 

293 

2,740 

960 

\  36 

(  24 

420 

11,00c 

877 

72 

2,800 

63,00C 

4,120 

68 

1,185 

,  59,00c 

)  371 

125 

5,540 

175,00( 

— 

GO 

80 

6,380 

102,00( 

)  6,760 

40 

U.  S.  Reservoir  Surveys  in  VS^yoming. 

1  I  Jackson  Lake  |  |     840  |  |  500,000|  . 

U.  S.  Reservoir  Surveys  in  Idaho. 
1  jSwan  Valley,  Snake  Riverl  |  5,365  |   |1 .500  0001 . . 


I  25 
.|  125 


390  APPENDIX. 

C'OST  OF  llESERVOm  CONBTRrCTION  PER  ACRE-FOOT.     AMERICAN  HeSERVOIRS. 


Name. 


Sweetwater  dam,  California. .  . . 
Bear  Valley  dam,        "       . . 

Hemet  dam,  "   

Escondido  dam,  "  .... 

Lower  Otay  dam,  " 

La  Mesa  dam,  "   

Cuyamaca  dam,  "  .... 

Buena  Vista  Lake,  "  .... 
Yosemite  Lake,  "  .... 

English  dam. 

Bowman  dam,  "  .... 

San  Leandro  dam,       ' '   

Eureka  Lake  dam,  "   

Fancherie  dam,  "       ....  . 

Lake  Avalon,  Pecos  Eiver,  N.  M 
Lake  McMillan  "        "  " 

Tyler,  Texas  

Cache  la  Poudre,  Colorado  

Larimer  and  Weld,  "   

Windsor,  "   

Monument,  "   

Apishapa,  "   

Hardscrabble,  "   

Boss  Lake,  "   

Saguache,  "   

Seligman,  Arizona  

Ash  Fork,  "   

"Williams,  "   

Walnut  Canyon,  Arizona  

New  Croton,  New  York  

Titicus,  "   

Sodom,  "   .... 

Bog  Brook,  "   

Indian  River,  **   

Wigwam,  Conn  


Character  of  Dam. 


Masonry 


Rock-fill 

Rock -fill,  steel  core 

Hydraulic-fill 

Earth 


Rock- fill  crib 

Earth 
Rock-fill 

a 

Rock- fill  and  earth 

Hydraulic-fill 
Earth 


Masonry 

Steel 

Masonry 

Masonry  and  earth 


Earth 

Masonry  and  earth 
Masonry 


Capacity  of 
Reservoir. 
Acre-feet. 


22,566 
40,U00 
10,500 
3.500 
42,190 
1,300 
11,410 
170,000 
15,000 
14,900 
21,070 
13,270 
15,170 
1,350 
6,300 
89,000 
1,770 
5,654 
11,550 
28,000 
885 
459 
102 
205 
954 
703 
110 
338 
480 
98,200 
22,000 
14,980 
12,720 
102,548 
1,028 


Cost. 


1264,500 
68,000 
150,000 
110,059 

i7,bbo 

54,400 
150,000 

* '155,000 
151,521 
900,000 
35,000 
8,000 
176,000 
180,000 
1.140 
110,266 
89,782 
75,000 
33,121 
14,772 
9,997 
14,654 
30,000 
150,000 
45,776 
52,838 
55,000 
4,150,573 
933,065 
366,990 
510,430 
83,555 
150,000 


APPENDIX. 


391 


Estimated  Cost  op  Reservoir  Construction  per  Acre-foot. 

American  Reservoirs. 


Projected 


Name. 


Tonto  Basin,  Arizona  

San  Carlos,  "   

Riverside,  " 

Bultes,  "   

Horseshoe,         '  *   

Bear  Canyon,  "   

Victor,  California  

Manache  Meadows,  California  . . 

Rock  Creek,  Nevada  

Columbus,  Oliio  

Elephant  Buttes,  New  Mexico. . . 
Pecos  River,  " 

Sand  Lake,  Texas.   

Laramie,  Wyoming  

Sweetwater  River,  "   

Cloud  Peak,  "   

Piney,  "   

Lake  De  Smet,  "   

Lov eland,  Colorado  

Tarrvall,  "   

Lost  Canyon  "   . . 


Charactei-  of  Dam. 


Maconry 


Rock-fill  &  mas'ry 

Rock-fill 

Masonry 

Rock- fill 

Masonry 

Rock-fill 
Natural  basin 

Masonry 

Rock-fill  and  earth 

Natural  basin 

Masonry 
Natural  rock-fill 


Capacity  of 
Reservoir. 
Acre-feet. 


757,000 
241,396 
221,13d 
174,040 
205,000 
14,762 
390,000 
146,400 
80,000 
17,440 
253,368 
200,000 
72,500 
414,000 
326,965 
6,800 
11,020 
67,628 
45,741 
46,000 
24,000 


Estimated 
Cost. 


,2,450,000 
1,038,926 
1,992,605 
2,643,327 
600,000 
596,530 
450,000 
130,000 
80,000 
324,177 
281,515 
150,000 
36,000 
1,416,254 
276,485 
31,049 
70,226 
113,110 
262,106 
550,000 
104,000 


Cost  per 
A  ere- foot  of 
Capacity. 


13.24 
4.30 
9.01 

15.19 
2.93 

40.40 
1.15 
0.89 
i.OO 

18.60 
1.11 
0.75 
0.50 
3.42 
0.85 
4.56 
6.37 
1.67 
5.73 

12.00 
4.35 


Cost  of  Reservoir  Construction  per  Acre- foot.    Foreign  Reservoirs. 


Name. 


Couzon,  France  

Furens,  "   

Ternay ,  "   

Ban,  "   

Pas  du  Riot,  "   

Chartrain,  "   

Lak^  Oredon,  "   

Moucue,  "  ....... 

Liez,  "   

Wassy,  "   

Patas,  India  

Ekruk,         "   .'. 

Ashti,  "   

Lake  Fife,  "  

Bhatgur,  "  

Tansa,  "   

Betwa.  "   

Chumbrumbaukum,  India 

Villar,  Spain   

Gilleppe,  Belgium  

Remsclieid    Germany. . . . 

Vyrnwy,  Wales  

Beetaloo,  Australia  


Character  of  Dam. 


Masonry 


Earth 
Masonry- 
Earth 


Earth  and  masonry 

Earth 

Masonry 


Earth 
Masonry 


Concrete 


Capacity  of 
Reservoir. 
Acre-f-eet. 


1,297 
1,297 
2,433 
1,499 
1,054 
3,647 
5,894 
7,011 
13,051 
1,740 
325 
76,175 
32,6(;0 
75,500 
126,500 
52,670 
36,800 
63,780 
13,050 
9,730 
811 
44,690 
2,945 


Cost. 


1247,600 
318,000 
204,372 
190,000 
256,000 
420,000 
142,000 

1,003,657 
598,418 
138.942 
15,925 
666.000 
270,000 
630,000 


988,000 
160,000 
312,000 
390,000 
874,000 
91,154 
,334,000 
573.300 


Cost  per 
A  ere- foot  of 
Capacity. 


$190.00 
245.00 
84.00 
127.00 
243.00 
115.10 
24.00 
143.00 
46.00 
80.00 
49.00 
8.74 
8.26 
8.34 


18.76 
4.35 
4.89 
28.88 
89.83 
112.45 
74.61 
194.70 


392 


APPENDIX, 


TABLES  OF  RESERVOIR  CAPACITIES  AND  AREAS. 

ESCONDIDO  IlUJIOATION  DISTRICT  ReSEKVOIR,  CALIFORNIA. 
[Area  of  trihiitaiy  watershed,  8  square  niile.s;  elevation  of  base  of  dam  above  sea-level,  1300  feet.] 


Heiglit 
above  Base 
of  Dam. 
Feet. 

Su 

•face  Area. 
Aeres. 

Capacity  of 
Reservoir. 

Acre-feet. 

Remarks. 

20 

46 

85 

288 

50 

970 

Capacity  of  reservoir  as  com- 

65 

2,400 

pleted  in  1895,  3,500  acre-feet. 

80 

174 

4,576 

Outlet  of  reservoir  is  16  feet 

90 

6,455 

above  base. 

101) 

8,693 

110 

"  285""; 

11,355 

J 

Lower  Otay  Reservoir,  California, 
[Area  of  tributarj'  watershed,  100  square  miles;  elevation  of  base  of  dam  above  sea-level,  345  feet.] 


Height 
above  Base 
of  Dam. 
Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

Remarks. 

30 
40 
50 
60 
70 
80 
90 
100 
]:-iO 
150 

40 
96 
160 
239 
276 
303 
452 
567 
1,000 
1,414 

321 
1.002 
2,284 
4,281 
6,860 
9.756 
13,530 
18,623 
42,190 
66,455 

Outlet  tunnel  48  feet  above  base 
)-    of  dam.    For  cross-section  of 
dam- site  see  Fig.  177,  p.  373. 

J 

Morena  Reservoir,  San  Diego  County,  Caijfornia. 
[Area  of  tributary  waterslied,  135  square  miles;  elevation  of  base  of  dam  above  sea-level,  3100  feet.] 


Height 
above  Base 
of  Dam. 

Surface  Area. 

Capacity  of 
Reservoir. 

Remarks. 

Feet. 

Acres. 

Acre-feet. 

50 

46 

460 

1 

60 

73 

1,079 

70 

111 

2,029 

80 

L52 

3,316 

Outlet  tunnel  is  at  30-foot  con- 

90 

225 

5,188 

tour.      Rock-fill   dam,  with 

100 

304 

7,831 

-    aspbalt  concrete  facing.  For 

110 

438 

11.466 

cross-section  of  dam-site  see 

120 

624 

16,804 

Fig.  177,  p.  373. 

130 

850 

24,107 

140 

1,137 

34.358 

150 

1,370 

46,733 

J 

APPENDIX. 


393 


La  Mesa  Reservoir,  San  Diego  County,  California. 

[Area  of  tributary  watershed,  5  square  miles;  elevation  of  base  of  dam  above  sea-level,  433.5  feet.] 


Height 
ibove  Base 
of  Dam. 
Feet. 


30 
35 
40 
45 
50 
55 
60 
65 
70 
75 
80 
85 
90 
95 
100 
140 


Surface  Area. 
Acres. 


12 
18 
24 
30 
41 
53 
62 
70 
83 
96 
113 
129 
152 
181 
205 
444 


Capacity  of 
Reservoir. 

Acre-feet. 


110 
190 
290 
430 
610 
850 
1,190 
1,460 
1,850 
2,290 
2,820 
3,420 
4,120 
4,950 
5,920 
18,890 


Remarks. 


Hydraulic-fill  dam,  completed 
)-    1895,  to  66-foot  contour.  Out- 
let at  base  of  dam. 


Pine  Valley  Reservoir,  San  Diego  County,  California. 
[Area  of  watershed,  45  square  miles;  elevation  of  base  of  dam,  3700  feet.] 


Height 
above  Base 
of  Dam. 

Surface  Area. 

Capacity  of 
Reservoir. 

Remarks. 

Feet. 

Acres. 

Acre-feet. 

40 

90 

550 

1 

50 

160 

1,800 

60 

240 

3,800 

65 

277 

5,100 

70 
80 
90 
100 
110 
120 

300 
315 
330 
349 
397 
520 

6,530 
9,610 
12,835 
16,230 
19,960 
24.540 

1  Dam  proposed  to  be  constructed 

1     by   Lydraulic   process   as  a 
y    rock-fill eartli-dam.  Forcross- 
1     section  of  dam  site,  see  Fig. 
177,  p.  873. 

125 

586 

27,080 

130 

640 

30,380 

140 

720 

37,180 

150 

784 

44,695 

J 

394 


APPENDIX. 


Lake  Hemet  Rkservoiu,  Riverside  County,  Califoiinia. 


[Area  of  watershed,  05  to  100  square  miles;  elevation  of  base  of  dam,  4200  feet.] 


rieifiiiD 
above  liase 

Surface  Area. 

Capacity  of 
Rit*s(3i'v  oil*. 

Remarks. 

of  l);iin. 

Feet. 

Acres. 

Acre-feet. 

40.0 

2.0 

33 

45.0 

2.3 

78 

Lowest  outlet  at  45  feet. 

50.0 

3.0 

118 

60  0 

29.0 

382 

70.0 

62.0 

778 

80.0 

103.0 

1,603 

90.0 

133.0 

2,787 

100.0 

187.0 

4,391 

110.0 

252.0 

6,598 

120.0 
122.5 

328.0  ' 
365.0 

9,512 
10,500 

Top  of  dam  as  completed  1895. 

130.0 

486.0 

13,590 

140.0 

601.0 

19,077 

150.0 

738.0 

25,836 

Little  Beau  Valley  Reservoir  (Arrowhead  Reskiivoir  Company),  San- 
Bernardino  County,  California. 


[Area  of  tributary  watershed,  e.6  square  miles;  elevatiou  of  base  of  dam,  4946.3  feet.] 


Heiglit 

Capacity  of 

above 

Surface  Area. 

Remarks. 

Tunnel 

Reservoh-. 

Outlet. 

Feet. 

Acres. 

Acre-feet. 

10 

29.7 

198 

20 

55.8 

619 

30 

77.0 

1,280 

40 

109.6 

2,207 
3,680 

50 

191.8 

60 

236.9 

5.830 

Bottom  of  outlet  tunnel  is  15.5 

70 

286.0 

8,414 

80 

386.3 

11,518 

feet  above  bed  of  creek  at 
^    base  of  dam;  lowest  founda- 

90 

395.8 

15,170 

100 

452.0 

19,401 

tions  about  15  feet  lower. 

110 

535.0 

24,826 

120 

626.0 

30,094 

135 

716.0 

40,144 

147 

800.0 

49,238 

160 

884.0 

60,179 

175 

932.0 

73,800 

APPENDIX. 


395 


Sweetwater  Dam,  San  Diego  County,  California. 

[Area  of  tributary  watershed,  186  square  miles;  elevation  of  lowest  outlet  above  sea-level,  140  feet.] 


Height 
above  Low- 
est Outlet. 
Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

Remarks. 

0.0 
10.0 
20.0 
80.0 
40.0 
50.0 
60.0 
70.0 
75.5 

3.5 
17.1 
75.2 
153.7 
272.2 
398.0 
539.0 
722.0 
895.0 

1 

.Lowest  outlet  is  24  feet  above 
'     lowest  fotindutions  of  dam. 

J 

94 
540 
1,679 
3,748 
7,066 
11,737 
18,053 
22,500 

Grass  Valley  Reservoir  site  (Arrowhead  Reservoir  Company)  San 
Bernardino  County,  California. 


[Area  of  tributary  watershed,  2.7  square  miles;  elevation  of  base  of  dam-site,  5108.3  feet.] 


Height 
above  Base 
of  Dam. 
Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

Height 
above  Base 
( f  Dam. 
Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

22 

5.4 

37 

92 

159.7 

5,946 

32 

29.5 

196 

102 

180.4 

7,632 

42 

52.8 

ro2 

112 

200.2 

9,550 

52 

72.8 

1,225 

122 

210.0 

11,635 

62 

100.7 

2,090 

125 

234.0 

12,329 

72 

115.7 

3,180 

150 

301.8 

19,010 

82 

138.0 

4,460 

175 

381.7 

27,547 

Huston  Flat  Reservoir  (Arrowhead  Reservoir  Company),  San 
Bernardino  County,  California. 


[Elevation  of  creek-bed  at  dam-site,  4450  feet.] 


Height 
above  Base 
of  Dam. 
Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acr«-feet. 

Height 
above  Base 
Reservoir. 
Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre- feet. 

20 

8.0 

60 

100 

157.1 

6,150 

80 

20.8 

200 

110 

180.5 

7,616 

40 

37.0 

486 

120 

206.0 

9,762 

50 

55.8 

947 

130 

234.0 

11,975 

60 

74.5 

1,595 

140 

257.9 

14,411 

70 

93.5 

2,430 

150 

283.2 

17.138 

80 

112.7 

3,459 

175 

329.5 

24.753 

90 

135.6 

4,700 

396 


APPENDIX. 


Pauba  Ke8ervoii{-site,  San  Diego  County,  California. 

[Area  of  tributary  watershed,  '61'i  square  miles;  elevation  of  base  of  dam,  1350  feet.] 


Hei^lit 
above  Base 
of  Dam. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre- feet. 

10 

10  7 

54 

20 

62.3 

441 

30 

110.5 

1,262 

40 

190.7 

2.760 

50 

282.8 

5,150 

60 

340.7 

8,250 

70 

447  0 

12,-,^U0 

80 

584.2 

17,355 

90 

689.4  , 

24,728 

100 

805.9 

32,200 

130 

1,214.0 

62,496 

140 

1,441.0 

75,770 

Remarks. 


I  Maximum  depth  to  bed  rock 
y  about  25  feet  in  center  of 
channel. 


Warner's  Ranch  Reservoir-site,  San  Luis  Rey  River,  San  Diego  County, 

California. 

[Area  of  tributary  watershed,  210  square  miles;  elevation  of  base  of  dam,  2613  feet.   For  cross-section 

of  dam-site  see  fig.  177,  p.  373.] 


Height  above 
Stream-bed. 

Feet. 

Sui'face  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

10 

42 

200 

20 

228 

1,565 

30 

739 

16,415 

40 

1.200 

16,140 

50 

1,532 

29,830 

60 

2,036 

47,710 

70 

2,695 

71,410 

80 

3,237 

103,500 

90 

4,437 

142,740 

100 

5,535 

193,200 

APPENDIX. 


397 


Santa  Maria  Valley  Reservoib-site,  San  Diego  County,  California. 

^rea  of  tributary  watershed.  60  square  miles;  elevation  of  base  of  dam,  1300  feet.    For  cross-section 
of  dam-site  see  Fig.  177,  p.  373.] 


Height  above 
Base  of  Dam. 

Surface  Area. 

Capacity  of 
Reservoir. 

Feet. 

Acre-feet. 

20 

7.6 

45 

30 

23.2 

199 

40 

41.3 

522 

50 

80.3 

1,108 

60 

154.3 

2,305 

70 

285.9 

4  500 

80 

561.3 

8,736 

Pamo  Valley  Reservoir-site,  San  Diego  County,  California. 

[Area  of  tributary  watershed,  125  square  miles;  elevation  of  base  of  dam,  803  feet.] 


Height 
ibove  Base   Surface  Area 
of  Dam. 


Feet. 


40 


50 
60 
70 
80 
90 
100 
110 
120 
130 
140 
150 
160 
170 
185 


401.4 
476.5 
614.8 
708.8 


Capacity  of 
Reservoir. 


Acre-feet. 


Remarks 


204 


438 
766 
1,242 
.  2,049 
3,305 
5,083 
7.374 
10,425 
14,127 
18.527 
24,065 
31,700 
38,300 
49,100 


Outlet  of  reservoir  to  be  at  tlie 
^0-foot  level.  For  cross-section 
of  dam-site,  see  Fig.  177,  p.  373, 


Dye  Valley  Reservoir- site,  San  Diego  County,  California. 

[Area  of  tributary  watershed,  5  square  miles;  elevation  of  base  of  dam,  2200  feet.] 


Height  above 

Capacity  of 

Base  of  Dam- 

Reservoir. 

Remarks. 

Feet. 

Acre-feet. 

80 

4,800 

To  be  fed  by  diversion  of  Santa  Ysabel 
Creek,    draining  30   square  miles  of 
mountain  territory. 

398 


ArPENDIX. 


CuYAMACA  Rkbekvoik,  San  Diego  County,  Califotinta. 


[Area  oi  tributary  watershed,  11.03  square 

miles;  elevation  of  dam,  about  4850  feet.l 

of  Dam. 

Surface  Area. 

Capacity  of 
Reservoir. 

Remaiks. 

Feet. 

Acres. 

Acre-feet. 

10 
13 
14 
IG 
18 
20 
22 
24 
2() 
28 
30 
32 
34 
35 

6 
44 
106 
178 
255 
346 
428 
519 
605 
684 
768 
842 
919 
959 

12 
60 
200 
490 
900 
1,520 
2,290 
3.240 
4.360 
'  5,650 
7.100 
8,710 
10,470 
11,410 

1 

Top  of  dam,  41.5  ft  et  above  base. 
>    Floor  of  wasieway  at  35-foot 
contour  above  base. 

i 

Baerett  Reservoir- site,  San  Diego  County,  California. 

[Ai-ea  of  ti 

ibutary  «  aterslied,  250  square  miles;  elevation  of  base  of  dam,  1600  feet.] 

Height 
above  Base 
of  Dam. 

Surface  Area. 

Capacity  of 
Reservoir. 

Remarks. 

Feet. 

Acres. 

Acre  feet. 

GO 
70 
80 
90 
100 
110 
120 
130 
140 
150 
IGO 
170 
175 

70 
97 
147 
183 
231 
285 
363 
469 
576 
662 
784 
871 
936 

586 
1,412 
2  611 
4,312 
6  322 
8  975 
12.123 
16,345 
21,530 
27,835 
35,160 
43,440 
47,970 

Used  as  a  diverting-dam,  to  the 
Leigbt  of  (50  feet,  for  diverting 
Morena  reservoir  water  to  tlie 
Lower  Otay  reservoir.  For 
cross-section  of  dam-site,  see 
Fig.  177,  p.  373. 

I 


APPENDIX,  399 
Upper  Otay  Keservoir-site,  ISan  Diego  County,  California. 

[Area  of  tributary  watershed,  8  square  miles;  elevation  of  base  of  dam,  480  feet.    For  cross-section  o£ 

dain-site  see  Fig.  177,  p.  3i3.j 


Heigh r,  above 
Base  of  Dam. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre  feet.. 

CO 

89 

643 

80 

178 

3,236 

100 

293 

7,871 

120 

452 

15,342 

Bear  Valley  Reservoir,  San  Bernardino  County,  California. 


[Area  of  tributary  watershed,  56  square  miles;  elevation  of  base  of  dam,  about  6200  feet.] 


Height 
above  Base 
of  Dam. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

Height 
above  Base 
of  Dam. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

15 

10 

52 

53 

1,859 

26,463 

20 

35 

159 

55 

1,960 

30,010 

25 

141 

411 

57 

2,069 

34,040 

30 

295 

1,558 

60 

2,251 

40,476 

35 

428 

3,347 

65 

2,532 

52,428 

40 

1,060 

7,166 

70 

2,812 

65,065 

45 

1,425 

13,357 

80 

3,3C0 

95,500 

50 

1,691 

21,139 

South  Antelope  Valley  Irrigation  Company's  Alpine  Reservoir,  Los 
Angeles  County,  California. 


[Area  of  tributary  watershed,  6  square  miles;  elevation  bottom  of  reservoir,  2779  feet.] 


Height 
above  Base 
of  Dam. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

Remarks. 

6 

106 

415  . 

5 

140 

1,031 

16 

170 

1.807 

Filled  by  8  miles  of  conduit  from 

21 

202 

2,734 

Little  Rock  Creek,  with  drain- 

26 

228 

3,808 

age  of  61  square  miles. 

31 

252 

5.008 

36 

277 

6,332 

400  ArPENDIX. 

Victor  Rkskrvoiu-site,  San  Bkknahdino  County,  California. 

[Area  of  tributary  watershed,  1200  square  miles;  elevation  of  base  of  dam,  2708  feet.] 


Height  above 
Base  of  Dam. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Rfservoir. 

Acre-feet. 

145 

7,718 

390,000 

San  Leandro  Reservoir,  Lake  Chabot,  Oakland  Waterworks,  California. 

[Area  of  tributary  reservoir,  50  square  miles;  elevation  of  base  of  liam  above  sea-level,  115  feet.] 


Height 
above  Base 
of  Dam. 

Feet. 

Surface  Area.  ■ 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

Remarks. 

80 
50 
70 
90 
110 
130 
150 
170 

0 

1,154 
3,635 
7,886 
14,038 
22,290 
32,780 
45,740 

Outlet  level. 

Higli-water  mark   at  present, 
.     120  feet  above  base;  capac- 
(     ity,  13, 11 5  acre-feet,  or  5,825,- 
845,000  gallons. 

J 

82 
165 
259 
355 
468 
576 
715 

IVIanache  Meadows  Reservoir-site,  South  Fork  Kern  River,  California. 

[Area  of  watershed,  155  square  miles;  elevjition  of  dam-site,  8200  feet.] 


Height  above 
Base  of  Dam. 

Feet. 


10 
20 
30 
40 
50 
60 
70 
80 
100 


Surface  Area. 
Acres. 


22 
146 
812 
1,865 
2,599 
3,254 
3,814 
4,420 
5,830 


Capacity  of 
Reservoir. 

Acre-feet. 


110 
954 
4,563 
18,827 
40,732 
69,885 
105.236 
146,419 
248,852 


APPENDIX. 


401 


Bia  Meadows  Reservoir- site,  Salmon  Fork  Kern  River,  California. 

[Area  of  watershed  (estimated),  25  square  miles.] 


Height  above 
Base  of  Dam. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

20 

81 

409 

80 

468 

8,174 

40 

603 

8,530 

50 

723 

15,169 

60 

802 

22,784 

70 

870 

31,148 

80 

930 

40,036 

100 

1,020 

59,311 

North  Fork  Lake  Reservoir- site.  Upper  Kern  River,  California, 


[Elevation,  6500  feet.] 


Height 
above  Base 
of  Dam. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

Remarks. 

20 
70 
120 
170 
220 

46 
104 
189 
318 
598 

Outlet  level. 

3,763 
11,101 
23.770 
46.614 

BuENA  Vista  Lake  Reservoir,  Lower  Kern  River,  California. 

[Elevation  above  sea-level,  260  feet.] 

Height 
above 
Outlet. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir. 

Acre-feet. 

Remarks. 

0 
10 

23,570 
25,000 

0 

170,000 

)  A  depth  of  6  feet  below  the  bot- 
V    torn  of  outlet-canal  is  never 
)     drawn  upon. 

402 


APPENDIX. 


ToNTo  Basin  Reseijvoir  pite,  Salt  River,  Arizona. 


[Area  of  watershed,  6-,*G0  square  miles;  elevation  of  base  of  dam,  1925  feet.] 


Heif^ht 
above  Dam 

vv^ater  Mark. 

Feet. 

Area  Flooded. 
Acres. 

Capacitv  of 
Krtisf  I'voi  I". 

Aci-e  feet. 

Heifrht 
aV)()VH  Dam 

water  Mark. 

Feet. 

Area  Flooded. 
Acres. 

Capacity  of 
Reservoir, 

Acre-feet. 

/CO 

1  9A 

.),ooU 

O  /I  1  OOA 

/541,oU0 

£)U 

0, 1  uu 

J 

6,210 

272,800 

35 

570 

9,000 

130 

6,570 

303,900 

40 

780 

11,900 

135 

6,950 

888,600 

45 

890 

16,200 

1-10 

7,350 

378,400 

50 

1,080 

20,000 

145 

7,980 

413.000 

55 

1,280 

2(5,900 

150 

8,580 

453,(100 

60 

1,510 

38  800 

155 

9,110 

498.000 

65 

1,740 

'  42,000 

160 

9,6b0 

544,000 

70 

1,980 

50,700 

165 

10,170 

594,000 

75 

2,300 

62,100 

170 

10,680 

645,000 

80 

2.610 

78.500 

175 

11,240 

701,000 

90 

8,430 

108,600 

180 

11,750 

757.000 

95 

3,820 

122,700 

185 

12,800 

820,000 

100 

4,210 

141,800 

190 

13,000 

880,000 

105 

4,610 

164,700 

195 

18,600 

950,000 

110 

4,990 

187,700 

200 

14,200 

1,020,000 

115 

5,430 

214,700 

Queen  Creek  Reservoir-site,  Arizona. 


[Area  of  watershed,  80  to  250  square  miles;  elevation  of  base  of  dam,  creek  bed,  2050  feet.] 


Height 
above  Base 
of  Dam. 

Feet. 

Surface  Area. 
Acres. 

Capacity  of 
Reservoir-. 

Acre-feet. 

Remarljs. 

20 

22 

190 

80 

52 

560 

40 

112 

1,380 

50 

209 

2,985 

60 

279 

5,425 

70 

856 

8.600 

Height  of  dam  suggested,  115 

80 

445 

12.605 

feet,  would  flow  to  the  height 

90 

538 

17.520 

of  110  feet. 

100 

630 

23,360 

110 

757 

30,795 

120 

894 

39,050 

130 

1.019 

48,615 

140 

1,191 

59.665 

APPENDIX. 


403 


BuTTES  Reservoir- BITE,  Gila  River,  Arizona. 
[Area  of  tributary  watershed,  13,750  square  miles;  elevatiou  of  base  of  darn  (low  water),  1600  feet.] 


Height 
above  Base 
of  Dam. 

Surface  Area. 

Capacity  of 
Reservoir. 

Remarks. 

Feet. 

Acres. 

Acre-feet. 

10 
20 
30 
40 
50 
60 
70 
80 
90 
100 
110 
120 
130 
140 
150 
160 
170 
180 
190 
200 

20 
71 
229 
397 
533 
741 
928 
1,105 
1,329 
1,566 
1,769 
2.029 
2,307 
2,746 
3,149 
8,002 
4,118 
4,6u9 
5,133 
5,651 

100 

550 
2,050 
5,180 
9,830 
16,200 
24,545 
34,710 
46,880 
61,355 
78,030 
97,020 
119,000 
144,565 
174,040 
207,795 
246,395 
290.000 
338.740 
392,660 

1 

Height  of  dam  proposed,  170 
)■    feet,  will  carry  160  feet  depth 
of  water. 

J 

umAiiv 

Oi-  THE 
liNlVERsn  v  oflLLlNOk 


tength"of  Crest  315  feet. 
CmUur  Jhtervia  10  feet 


CALIFORNIA. 


TUOLUMNE  MEADOTO  RESERVOIR  SITE 

Wm. Ham, Han,  Engineer 
Lutlier  IVagoner.  Asst.En^T 


Maximum  Capacity  43,185  Acre  Feet. 

SCALE: 


Contour  Interval  10ft. 
1689. 


Height    IIS  ft 
Length  of  Crest  915  feet. 

Cantnu  HUervei  10  feet 


-ITO 
■ISO 


PLAN  AND  PROFILE 
or 

DAM  SITE 

Height    115  F* 
Length  of  Crest  315  feet. 

CmtUw  Interval  10  feet 


3 

CALIFORNIA 

mm  mmm  n^nmm  ^Y^rm. 

LITTLE  YOSEMITE  RESERVOIR  SITE 
Win.Ham.HaIl.  ETigineer. 
Lutlier  Wagoner, 
Maximum  Capacity  45,)35  Acre  Feet 


Centaur  Interval  10ft 


UiSHAHf 


UMkAHV 


imAHY 

M*.-n  THE 


0}-  THE 
MNIVERSITY  oflLLlNOl 


U^ffVWSif/oflLLINOk 


\ 


1 


PBELMENARY  PLAl 

flKi©EPEKi©Et^©i  LAKE  mBmmm$WE, 

"WSiuHam-Han,  Sttpervisin^Ejogr. 
LjTiiarLBridges ,  Engineer. 


Maximum  Capacity  23707  Acre'Ft. 

SCALE:  a  INCHES  <=! MILE. 

V.A-  9   


Contour  IntervaZ  5  ft. 
1889. 


LiBHARY 
UWiVEHSITY  ofiLLlNOU 


r 


g  LAHONTAN  BASIN 

PBFiT.TMINABY  PLAT 

'EiiEi^  LAKE  m^Em^m  site, 

W3Ti.Haiix.HnU,  Sxii3orv:g  Eixgi". 


Maximum  Capacity  lll52  AcreFt. 

SCALE:  atNCHES  =  I  MILE  . 


Coiitaiir  Interval^  5  feet. 
1889 


PROFILE  OF  DAM  SITE. 

Maximum  Height  29  Ft. 
Length  of  Great  SIZFeet. 

NATURAL.  S6ALE  :  150  FEET  =  I  INCH. 
1^0     100      50      0  [50  FT. 


01-  THE 
UNiVtRSlTY  oflLllNOit 


PLA 

I 

Maxim 
Lengtl 

NATURAL  SI 
100 


1 

] 


i 


i 

] 


\ 


£ 


\ 


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\ 


iMm(¥ 

Of-  TWE 


Of-  THE 


\ 


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\ 


1 


ONlV£RS^•VoflLUNO!^ 


t>9 


Lmmv 


i 


! 


I 


! 


MONTANA 

BUM  Rwm  mBmmm  system 

RESERVOIR  N?  8. 

H.M.TVUson.Erisineer. 
Jno  B.Rogers. Aflsl.En^r 


Maximum  Capacity  1735  Aore  Feet 


\ 


i 


~  I 


\ 


LIBRARY 

Of-  THE 
UNIVERSITY  of  ILLINOU 


\ 


I 


i 


i 


INDEX. 


Agua  Fria  : 

dam,  206-217 

reservoir,  206 

river,  206 
Algiers,  dams,  123 
Alicante,  Spain  : 

dam,  252 

reservoir,  252 
Allen,  Chas.  P.,  67 
Almanza  dam,  Spain,  252 
Alpine  reservoir,  299,  303,  399 
American  River,  179 
Anderson,  Col.  Latham,  116 
Apishapa  state  dam,  Colo.,  297 
Apportionment  of  water,  Hemet  district, 
163 

Aqueduct  Commission,  N.  Y.,  237,  238 
Arcli  dam,  119 
Area  : 

Hemet  irrigation,  163 
Pecos  Valley,  362,  363 
Areas  : 

reservoir,  392-403 
watershed,  392-403 
Arizona  reservoir  surveys,  320 
Arrowhead  Reservoir  Company,  368 
Ash  Fork,  Arizona  : 
reservoir,  214 
steel  dam,  214,  222-226 
Ashti  dam,  settlement  of,  279 
Ashti  tank,  India,  277-279 
Asphalt  concrete,  36,  208 
Asphalt,  use  of,  for  protection  of  steel  core 

of  Otay  dam,  21 
Assiout  dam.  Upper  Egypt,  273 
Assuan  dam,  Egypt,  273 
Austin,  Tex.: 

dam,  242-247 
failure  of,  246 
reservoir,  245 


Ayraard,  M.,  253 

Babcock,E.  S.,  20 

Bainbridge,  F.  H.,  222 

Balanced  valves,  31,  67,  68 

Ban  dam,  France,  256,  391 

Barrett  dam,  California,  32-35,  398 

Barton,  E.  H.,  179 

Basin  Creek,  Mont.,  dam,  230-235 

Bear  Canyon  dam,  Arizona,  350,  391 

Bear  Valley  dam,  California,  120,  125,  163- 

174,  399 
Bear  Valley  Irrigation  Co.,  163 
Beetaloo  dam,  S.  Aus.,  122,  271,  391 
Betwa  dam,  India,  269,  391 
Bhatgur  dam,  India,  267,  391 
Bidaut,  M.,  260,  261 

Big  Meadows  reservoir-site,  Cal.,  383,  401 
Blake,  Prof.  W.  P.,  59,  63 
Blasting,  types  of  heavy  blasts  : 

Lower  Otay  dam,  27,  29 

Morena  dam,  39 
Blauvelt,  Louis  D.,  49 
Bog  Brook  reservoir,  New  York,  238 
Boiler,  Alfred  P.,  45 
Bombay,  India,  water-supply,  266 
Bonds,  La  Grange  dam,  178 
Boss  Lake,  state  dam,  Colo.,  297,  298 
Bostaph,  V^.  M.,  66 
Bousey  dam,  France,  258,  259 

failure  of  258 
Bouvier,  M.,  256 
Bowie,  A.  J..  73 

Bowman  rock-fill  dam,  California,  74,  75 

reservoir,  74 
Boyd's  Corner,  New  York  : 
~  dam,  239 
reservoir,  239 
Brick  and  asphalt  facing  of  Remscheid 
dam,  Germany,  261 

405 


406 


IJSDEX. 


Bridgeport,  Conn.: 
dam,  241 
reservoir,  241 
Brodie,  Maj.  Alex.  O.,  63 
Brown,  V.  E  ,  164 
Buena  Vista  Lake,  California  : 
dam,  293 

reservoir,  293,  401 
Burns,  II.  B.,  223 

Cable\Aay,  180 

Lidgerwood,  22,  39,  235 
Cache  la  Poudre,  Colo.; 

dam,  295,  296 

reservoir,  295,  296 
Cagliari  dam,  Italy,  262 
Caimanche,  Texas,  reservoir-site,  362 
Cambie,  H.  J.,  105 
Campbell,  J.  L.,  361 

Canadian  Pacific  Lydraulic  fills  on 

100,  101,  105,  106,  107,  109 
Canal  : 

Modesto,  178 

Poona  reservoir,  267 

Siphoning,  across  Rio  Grande  River 

360 
Turlock,  178 
Canal  lines,  Rock  Creek,  363,  364,  366 
C'apacity  of  reservoirs,  75,  392-403 
Castlewood,  Colo. : 
canals,  45 
dam,  43-47 
reservoirs,  45 
Catchment  : 

Escondido  reservoir,  18 
Otay  Creek,. 27 
Cauverypauk  tank,  277 
Cedar  logs,  use  of,  Walnut  Grove  dam, 
61 

Cement,  21,  31 

mixing,  Hemet  dam,  154 
Center  core.  Lake  Christine  dam,  100 
Ceylon  tank,  274 
Cliabot,  A.,  77 

Cbartrain  dam,  France,  258,  391 
Chatsworth  Park  dam.  California,  42-44 
Chazilly  dam,  France,  255 
Chittenden,  Capt.  H.  M.,  71,  310,  320 
Cburabrumbankum  tank,  277,  391 
Clerke,  W.  T.  C,  267 
Cloud,  H.  H.,  49 

Ciond  Peak,  reservoir-site,  Wyo.,  316,  391 


Coleman,  J.  S.,  237 
Colorado  state  dams,  296 
Columbia  Colonization  Co.,  Cal  374 
Concrete,  31,  66,  67,  117,  271  * 

Ash  Fork  dam,  223 

base  Alpine  reservoir  gates,  304 

collars,  147 

dam,  189,  229-233,  271 
La  Mesa  dam,  90 
mixer,  147 

mixing,  San  Mateo  dam,  192,  193 
San  Mateo  dam,  189 
Conduit  : 

Escondido  reservoir,  5 
La  Mesa  dam,  90 
Sweetwater  dam,  152 
Congressional  River  and  Harbor  Act,  71 
Construction  plant,  Hemet  dam,  16l' 
Convict  labor,  Folsom  dam,  179 
Contents  Basin  Creek  dam,  Mont.,  235 
Cornell  University  dam,  240 
Cost  of  : 

Ash  Fork  dam,  224 
Assuan  dam,  273 
Austin  dam,  245,  251 
Bear  Canyon  reservoir,  351,  391 
Bear  Valley  dam,  165 
Bowman  dam,  74 
cement,  Bear  Valley  dam,  164 
conduit  Sweetwater  dam,  152 
Denver  V^ater  Co's.  dam'  71 
English  dam,  73 
Escondido  dam,  14,  15 
hydraulic  filling  Canadian  Pacific  Ry 
105,  106 

liydraulic  filling  Northern  Pacific  Ry 
114  ^" 

Indian  River  dam,  240 

La  Grange  dam,  176 

Lake  Christine  dam,  100 

Lake  McMillan  dam,  53 

materials,  Hemet  dam,  154 

New  Croton  dam,  237 

Norway,  Mich.,  dam,  236 

Pacoima  dam,  206 

Padavil  tank,  275 

Periyar  dam,  271 

reservoir  construction,  390,  391 

Rio  Grande  reservoirs,  proposed,  359 

Rio  Verde  reservoirs,  348,  350 

San  Leandrodam,  77 

Segilman  dam,  220 


INDEX. 


Cost  of  : 

Sodom  dam,  238 
Sweetwater  dam,  137,  395 
Titicus  dam,  237 
Tyler  dam,  84 

Victor  reservoir  and  canals,  380,  391 

Vyrnwy  dam,  262,  263 

Walnut  Canyon  dam,  226 

Williams  dam,  231 
Cotatay  dam,  France,  257 
Coventry,  W^  B.,  118 
Cracking  of  dams,  122,  148 
Cross-section,  Agua  Fria  dam  and  reservoir, 
213 

Cross-sections,  dam-sites,  San  Diego  Co., 
373 

Crowe,  H.  S.,  179 
Crugnola,  G.,  264 

Crystal  Springs  reservoir,  California,  203 
Curved  dams,  118,  120,  121,  122 
Cushion,  water,  120 
Cuyamaca  dam,  281,  398 

Dam  : 

cracking  of,  122,  148 

curved.  119-122 

earthen,  267 

hydraulic-fill,  76 

masonry,  117 

necessary  width  of,  119 

rock-fill,  1 
Dam-sites,  see  Reservoir-sites. 
Davis,  Arthur  P.,  321 
Davis,  Chester  B.,  230 
Davis  and  Weber  Counties  Canal  Company, 
64 

Deacon,  Geo.  F.,  263 

Delocre,  M  ,  118,  121,  256 

Denver  Water  Company's  dam,  66-70 

reservoir,  71 
Derricks,  39,  131 

use  of,  at  Walnut  Grove  dam,  60 

water  power,  161 
Design  and  construction  of  dams,  252 
Design,  conditions  of  Bhatgur  dam,  268 
Details  of  Sweetwater  dam,  146 
Dimensions  : 

Barrett  dam,  32 

Bear  Valley  dam,  164 

Bridgeport  dam,  239 

La  Grange  dam,  176 

Seligman  dam,  220 


Distributing  system  Escondido  reservoir,  14 
Distributing  system  Sweetwater  reservoir, 
152 

Diverting  dam,  206-217 

Fort  Selden,  N.  M.,  354,  357 
Djidionia  dam,  Algiers,  265 
Drainage  area  : 

Colorado  River,  245 

English  dam,  71 

Indian  River  reservoir,  240 
Duchesnay,  Edmund,  105 
Dulzura  conduit,  32 
Dulzura  Pass,  27 
Duty  of  water,  Pecos  Valley,  58 

Earthen  dams  : 

Apishapa  state,  Colo.,  297 
Boss  Lake  state,  Colo.,  297,  298 
Buena  Vista  Lake,  Cal.,  293,  401 
Cache  la  Poudre,  Colo,,  295 
Cuyamaca,  Cal.,  281-289 
experiments  on  materials  for,  116 
Hardscrabble  state,  Colo.,  297 
history  of,  274-279 
India,  274-280 

Merced  reservoir,  California,  289 
modes  of  construction,  280 
Monument  Creek,  Colo.,  296 
Pilarcitos,  California,  294,  295 
Saguache  state,  Colo,,  298 
San  Andres,  California,  294,  295 

Earth,  packing  of,  in  earthen  dams,  281 

Earthquake  crack.  Southern  California,  299 

East  Canyon  Creek  dam,  Utah,  64,  65 

Eastward,  J.  S.,  99 

Einsiedel  dam,  Germany,  262 

Ekruk  tank,  277 

El  Cajon  Valley,  125 

Elche  dam,  Spain,  252 

Elephant  Butte,  New  Mexico  : 
dam,  352 

reservoir,  354-356 
El  Molino  dam,  California,  125 
El  Paso,  Texas,  international  dam,  351 
Embankments,  Madras,  275 
English  dam,  Cal.,  71-74 

failure  of,  73 

flood-wave  from  bursting  of,  78 

reservoir,  71 
Escondido  dam,  California,  2-19,  392 

distributing  system,  14 
Escondido,  irrigation  district  map,  Z 


408 


INDEX, 


Evaporation,  174 

Assuan  reservoir,  373 

Buena  Vista  Lake  reservoir,  294 

Cuyamaca,  285 

Rio  Grande  River,  362 

Sweetwater  reservoir,  152 

Tansa  dam,  266 
Explosion  of  heavy  blasts,  Lower  Otay 
rock-fill  dam,  29 

Failure  of  dams : 

Austin  dam,  246,  251 

Bousey  dam,  258 

Habra  dam,  263 

Lynx  Creek  dam,  228 

Puentes  dam,  253 
Fanning  J.  T.,  242 
Farren,  George,  121 
Feeder  canal : 

Escondido  irrigation  district,  3 

Little  Rock  Creek,  300 
Feeder  conduit,  Escondido  irrigation  dis- 
trict, 6 

Fisbway,  Twin  Lakes  reservoir,  Colo.,  307 

Floods  of  the  Nile,  273 

Flood-wave  from  bursting  of  a  California 

dam,  78 
Folsom  dam,  179-189 
Forcbbeimer,  Prof.,  121 
Fortier,  Prof.  S.,  66,  116 
Frizell,  Jos.  P.,  242 
Fteley,  A.,  235,  238 
Fuertes,  Prof.  E.  A.,  241 
Furens  dam,  118,  391 

Gates  : 

concrete  base  for,  304 
Escondido  dam,  11,  13 
quick-opening,  Lake  Avalon  reservoir, 
51 

railroad,  279 

stems,  99 

valve,  90,  131 
Geelong  dam,  Aus.,  271 
Giants'  tank,  Ceylon,  275 
Gila  River,  Arizona,  proposed  reservoirs 
on,  339 

Gileppe  dam,  Belgium,  260,  391 
Glacial  Flour,  309 

Gophers,  guarding  reservoir  against,  163 
Gorzente  dam,  Italy,  262 
Go  wen,  Cbas.  F.,  237 


GraefE,  M.,  256 

Gran  Cbeurfas  dam,  Algiers,  265 

Grands-Cheurfas  dam,  123 

Gravel,  natural  storage-reservoirs  in,  311 

Gravity  dam,  116 

Greenalcb,  W.,  240 

Gros-Bois  dam,  France,  254 

Grunsky,  C.  E.,  280 

Guadalantin  River,  253 

Habra  dam,  Algiers,  122,  263-265 

failure  of,  264 
Ha-miz  dam,  Algiers,  122,  265 
Hardscrabble  state  dam,  297 
Hassayampa  River,  58 
Headgates  Lake  Avalon,  N".  M.,  dam,  50 
Hemet  dam,  California,  152-163 
construction  plant,  161 
reservoir,  159 
Herschel,  Clemens,  116 
Hi  jar  dam,  Spain,  254 
Hill,  A.,  268 
Hilton  cement,  235 
Holyoke  dam,  116 
Homogeneity,  masonry  dams,  117 
Hooker,  Elon  H.,  241 
Horse-power,  use  of,  for  derricks,  131 
Horseshoe  reservoir-site,  348,  391 
Howells,  J.  M.,  78,  84,  99 
Hudson  Canal  and  Reservoir  Company,  343 
Hyde,  F.  S.,  285 
Hydraulic  construction  : 
Georgia,  116 
Seattle,  Wash.,  115 
Tacoma,  Wash.,  115 
Hydraulic  cylinder,  68 
Hydraulic-fill  dam  construction,  76 
Hydraulic- fill  dams  : 

Holyoke,  Mass.,  116 
Lake  Christine,  98-100 
La  Mesa,  84-98 
San  Leandro,  77,  78 
Temescal,  77,  78 
Tyler,  Texas,  78-84 
Hydraulic  filling,  Canadian  Pacific  Ry., 

100,  101,  105,  106,  107,  109 
Hydraulic  filling  Northern  Pacific  Ry., 

106,111,114 
Hydraulic  jack  for  raising  shutter,  Fol- 
som dam,  189 
Hydraulic  mining  districts,  Northern  Cal., 
75 


INDEX. 


409 


Impounding  reservoirs,  121 

Improved  cement,  241 

Independence,  Cal.,  liigli  mountain  lake 

tapped,  384 
Indian  River,  New  York  : 

dam,  239 

reservoir.  240 
Inlet  valves,  131 
Inlet  tower,  131 

Interlocking  masonry  dams,  117 
Intze,  Prof.,  121,  262 
Investigation,  reservoir-sites,  321 
Irrigated  lands,  Hemet,  153 
Irrigation  area,  Sweetwater,  149 

Jolinstovrn,  Penn.,  73,  281 

Kelly,  Wm.,  236 
Kern  Lake  reservoir-site,  383 
Kern-Rand  Reservoir   and  Electric  Com- 
pany, 382 
Kern  River,  Cal.,  reservoir-sites,  380 
Kingman,    Ariz,,    submerged   dam,  214, 
°219 

Krantz,  J.  B.,  121,  256 
Krantz,  M.,  256 

La  Grange  dam,  Cal.,  174-179 
Lake  Avalon,  N.  M.,  dam,  47-52 
Lake  Christine,  California,  bydraulic-fill 
dam,  98 

Lake  De  Smet,  Wyo.,  reservoir-site,  310, 
391 

Lake  Hemet,  153,  394 
Lake  McMillan  : 

dam,  51,  53 

reservoir,  53 
Lakes,  Sierra  Nevada  Mts.,  383 
La  Mesa,  Cal.: 

dam,  20,  84,  95.  98,  393 

reservoir,  91,  97 
Land,  Gordon,  296 
Larimer  and  Weld  reservoir,  309 
Larimie  reservoir-site,  310,  391 
Leakage : 

Escondido  dam,  11 

Sweetwater  dam,  148 

Walnut  Canyon  dam,  227 

Walnut  Creek  dam,  60 
Linda  Vista  irrigation  district,  373 
Lippincott,  J.  B.,  174.  302,  321,  339 
Little  Bear  Valley  reservoir,  371,  394 


Little  Bear  Valley  reservoir-site,  367 
Little  Rock  Creek  irrigation  district,  373 
Loss  of  life  : 

Bousey  dam  failure,  258 
Habra  dam  failure,  263 
Johnstown  dam  failure,  281 
Puentes  dam  failure,  253 
Walnut  Grove  dam  failure,  60 
Loss  of  water,  Assuan  reservoir,  273 
Lost  Canyon,  Colo.: 

natural  dam,  363,  391 
reservoir-site,  366 
Lower  Otay,  rock-fill  steel-core  dam,  19- 

32,  392 
Lozoya  dam,  Spain,  254 
Ludlow  gates,  226 
Ludlow  valves,  06 
Lux  m.  Haggin,  293 
Lynx  Creek  dam,  Ariz,,  228,  229 
failure,  228 

Mac  Kenzie,  A.  T.,  270 
Man,  A.  P.,  341 

Manacbe  Meadows  dam  and  reservoir,  380, 

381,391,400 
Marston  Lake^  Colo.,  310 
Masonry  dams  : 

Agua  Fria,  Ariz.,  206-217 

Alicante,  Spain,  252 

Almanza.  Spain,  252 

Assiout,  Upper  Egypt,  273 

Assuan,  Egypt,  272 

Austin,  Texas,  242-251 

Ban,  France,  256,  391 

Basin  Creek,  Mont.,  230-235 

Bear  Valley,  California,  163-174,  399 

Beetaloo,  S.  Aus.,  271,  391 

Betwa,  India,  269 

Bbatgur,  India.  267,  391 

Bousey,  France,  258 

Boyd's  Corner,  New  York,  239 

Bridgeport,  Conn.,  241 

Cagliari,  Italy,  262 

Cbartrain,  France,  258 

Cbazilly.  France,  255 

Cotatay.  France,  257 

Cornell  University,  New  York,  240 

Djidionia,  Algiers.  265 

Eiiisiedel,  Germany,  262 

Elcbe,  Spain,  253 

essential  features  of,  258 

Folsom,  California,  179,  189 


410 


INDEX. 


Mtisoniy  dams  : 

Fiirens,  Prance,  255,  391 

Geeloiig,  Australia,  271 

general  principles  of,  118,  119 

Uilleppe,  Belgium,  260 

Gorzente,  Italy,  262 

Ciran  Cbeurfas,  Algiers,  265 

Gros  Bois,  France,  254 

Habra,  Algiers,  263 

Hamiz,  Algiers,  265 

Hemet,  California,  152-163 

Hijar,  Spain,  254 

Indian  Kiver,  New  York,  239 

Kingman,  Arizona,  214,  217 

La  Grange,  California,  174-178 

Lozoya,  Sjjain,  254 

Lynx  Creek,  Ariz.,  228,  229 

Mexican,  251 

Moucbe,  France,  260,  391 

New  Croton,  N,  Y.,  236 

Nijar,  Spain,  254 

Norway,  Micb.,  235,  236 

Old  Mission,  California,  125 

Pacoima,  Cal.,  submerged  dam,  205-211 

Pas  Du  Riot,  France,  257,  391 

Periyar,  India,  269 

Pont,  France,  257 

Poona  or  Lake  Fife,  India,  267,  391 

Portland,  Oregon,  229-233 

Puentes,  Spain,  253 

Remscbeid,  Germany,  261,  391 

San  Mateo,  California,  189-205 

Seligman,  Arizona,  214,  219-221 

Sodom,  New  York.  238,  239 

Sweetwater,  California,  20,  120,  122, 
125,  126-152,  395 

Tansa,  India,  266 

Ternay,  France,  256,  391 

Titicus,  New  York,  237 

Tlelat,  Algiers,  265 

Tytam,  Cbina,  272 

Val  de  Infierno,  Spain,  253 

Verdon,  France,  257 

Villar,  Spain,  254,  391 

Vingeanne,  France,  256 

Vvrnwy,  Wales,  262,  391 

Walnut  Canyon,  Arizona,  214,  225-228 

Wigwam,  Conn.,  241 

Williams,  Arizona,  214,  224 

Zola,  France,  255 
Matbematics,  of  curved  dams,  121 
Maxwell,  J.  P.,  297 


McDowell  reservoir-site,  348,  349 

McIIenry,  E.  II.,  Ill 

McBeynolds,  0.  O.,  307,  308 

Measuring-box,  212 

Merced  reservoir-dam,  289 

Mexican  dams,  251 

Mills,  Major  A.,  351,  361 

Mining   leservoirs    Nortbern  California, 

capacities  of,  75 
"Modern  Mexico,"  acknowledgments  to, 

251 

Modesto  irrigation  district,  Cal.,  176,  179 

Moles wortb,  Guilford  L.,  118 

Moncrieff,  J.  C.  B.,  271 

Montgolfier,  M.,  256 

Monument  Creek  dam,  Colo.,  296 

Morena  dam,  California,  19,  35-41,  392 

outlet,  39 

reservoir,  40 
Mormon  Canyon,  Cal.,  42 
Moucbe  dam,  122,  200,  391 
Mountain  pine  for  conduits,  162 
Movable  sbutter,  for  increasing  beigbt  of 
water  at  low  stage,  Folsom  dam, 
Cal.,  189 
Mudduk  Masur,  277 

Natural  dam.  Lost  Canyon,  363-366 

Natural  reservoirs  : 
Alpine,  Cab,  299 
Gravel-bed  storage-reservoirs,  311 
Lake  De  Smet   reservoir-site,  Wyo., 
310 

Laramie  reservoir-site,  Wyo.,  310 
Larimer  and  Weld,  Colo.,  309 
Loveland  reservoir-site,  Colo.,  310 
Marston  Lake,  Colo.,  310 
Twin  Lakes,  Colo.,  303 

Nettleton,  E.  S.,  49 

New  Croton  dam,  N.  Y.,  236 

Newell  curve  sbowing  relation  of  run-off 
to  rainfall,  204,  205,  285 

Newell,  F.  H.,  203 

Nicbolson,  W.  D.,  223 

Nijar  dam,  Spain,  254 

Nira  canal,  India,  268 

Nortbern  Pacific  By.,  111-114 

Norway,  Micb.,  dam,  235,  236 

Nueces  reservoir-site,  '1  exas,  362 

Old  Mission  dam,  San  Diego,  Cal.,  125 
Otay  Creek,  Cal.,  19 


INDEX. 


411 


Outlet : 

Alpine  reservoir,  303-307 

Asli  Fork  dam,  223 

Bear  Valley  dam,  166 

Denver  Water  Company's  dam,  67 

East  Canyon  Cieek  dam,  66 

Ilemet  dam,  162 

Lake  Christine  dam,  100 

Lake  McMillan  dam,  53 

Merced  reservoir  dam,  289 

Monument  Creek  dam,  296 

Morena  dam,  39 

San  Mateo  dam,  203 

Seligman  dam,  221 

Twin  Lakes  reservoir,  308 

Walnut  Canyon  dam,  226 

Walnut  Grove  dam,  61 
Outlet-gate,  La  Mesa  dam,  93 
Outlet  pipes,  131 

building  of,  281 
Outlet  tunnel : 

Lower  Otay  dam,  31 

Morena  dam,  39 


Pacoima  Creek,  205 

submerged  dam,  205-211 
Padavil  : 

tank  of,  274 

cost  of  embankment,  275 
Parabola,  221 

Parabolic  curve,  for  top  of  dam,  223 
Paraffine  paint,  61 
Pas  Du  Riot  dam,  France,  257,  391 
Pecos  : 

canal,  47 

Irrigation  and  Improvement  Company, 
47 

River,  54 

Valley  dam,  47,  391 

Valley,  area  of  arable,  irrigable  land 
in,  362.  363 
Pelletrean,  M  ,  121 
Pennycuick,  Col.,  271 
Percolation,  rate  of,  376 
Periyar  dam,  India,  269 
Pick-up  weir,  162 

bead  of  distributing  s  stem  Escondido 
irrigation  works,  14 
Pilarcitos  dam,  California,  295 
Piling  for  dam  foundation,  356 
Piney,  reservoir-site,  Wyo.,  316,  391 


Plan  : 

Folsom  dam,  179 

Pacoima  dam,  211 

San  Mateo  dam,  195 

Sweetwater  dam,  145 
Pont  dam,  France,  257 
Poona,  or  Lake  Fife  dam,  India,  267 
Portland  cement,  21,  117,  179,  205 
Portland,  Oregon,  concrete  dams,  229,  233 

reservoirs,  229,  230,  233 
Power  drop,  Folsom  canal,  179 
Precipitation  : 

Bear  Valley,  174 

data  on  U.  S.  weather  bureau,  57 

Puentes  dam,  253 

Spring  Valley,  California,  203 

Salt  River  watershed,  Ariz.,  343 

Victor  watershed,  376 
Pressure  Puentes  dam,  253 
Pressures,  maxima,  of  dams,  119 

greatest  recorded,  of   water  on  ma- 
sonry, 236 
Profiles  : 

Bear  Valley,    Sweetwater,  and  Zola 
dams,  120 

Projected  reservoirs,  see  Reservoir-sites. 
Puddle  core,  281 

Puddle  core  hydraulic  dams,  77,  100 
Puentes  dam,  Spain,  253 
Pumping  plants,  Sweetwater  district,  Cal- 
ifornia, 150,  151 

Quarries,  60 

Quarry,  Lower  Otay  dam,  27 
Quick-opening  gates.  Lake  Avalon  reser- 
voir, 51 
Quicklime,  ITabra  dam,  264 
Quinton,  J.  IL,  339 

Rafter,  Geo.  W.,  240 
Rainfall,  Cuyamaca  reservoir,  285 
Rain  gauges,  Little  Bear  Valley,  371 
Railroad  gates,  296 

Rate  of  flow,  underground  waters.  302 
Redwood,  facing  Escondido  dam,  7 

conduit,  162 
Remscheid  dam,  Germany,  121,  261,  391 
Reservoir  : 

areas.  392,  403 

Ash  Fork,  223-226 

Bear  Valley,  166,  174,  175 

Bowman,  74 


412 


INDEX. 


Reservoir  : 

Bridgeport,  241 
Capacities,  392,  403 
Construction,  by  general  government, 
330 

cost  of  construction,  390,  391 
Denver  Water  Company's,  71 
elevation  of,  392,  403 
Habra  dam,  263 
Hemet,  capacity  of,  163 
Indian  River,  240 
La  Mesa,  91,  97 
Lower  Otay,  26-28,  392 
•  Morena,  40,  393 
Rock  Creek,  363,  364,  391 
San  Leandro,  78 
Seligman,  221 
Sodom,  238 

Soutli  Antelope  Irrigation  Company, 
301 

Sweetwater,  137,  395 
Wigwam,  242 
Williams,  224 
Reservoirs  : 

Ceylon,  276 
natural,  299 

near  San  Diego,  Cal, ,  41 

Portland,  Oregon,  230 

projected,  see  Reservoir-sites. 
Reservoir  projects  : 

California,  370 

San  Diego  County,  373 
Reservoir-sites  : 

Bear  Canyon,  Ariz.,  BoO,  391 

Big  Meadows,  Cal.,  383,  401 

CaimancUe,  Texas,  361 

Cloud  Peak,  Wyo.,  316,  391 

data  on,  386,  403 

Elephant  Butte,  Texas,  351,  391 

El  Paso  international,  Texas,  351 

Horseshoe,  Ariz.,  344 

Kern  Lake.  Cal.,  383 

Kern  River,  Cal.,  380,  383 

Little  Bear  Valley,  Cal.,  367 
map,  175 

Lost  Canyon,  Colo.,  363,  391 

Manaclie  Meadows,  Cal.,  380,  391,  400 

McDowell,  Ariz.,  348 

Nueces  River,  Texas,  363 

Piney,  Wyo.,  316 

recommendations  on,  321-323 

Rock  Creek,  Nov.,  363,  391 


Reservoir-sites  : 

San  Carlos.  Ariz.,  330,  391 

San  Diego  County,  Cal.,  373 

Sand  Lake,  Texas,  362,  391 

selection  by  U.  S.  Geolog.  Survey, 
314,  321 

Swan  Lake,  Idaho,  314 

Sweetwater,  Wyo.,  315.  391 

Tonto  Basin,  Ariz.,  339,  391,  402 

Upper  Pecos,  Texas,  362 

Victor,  Cal.,  373,  391,  402 
Reservoir  surveys,  U.  S.,  314,  321,  348-351 
Rio  Grande  Dam  and  Irrigation  Company, 

352-354 
Rio  Grande  River  : 

evaporation  from,  361 

proposed  reservoirs,  351 

silt  of,  361 

water-supply  of,  360 
Rio  Verde  Canal  Company,  344 
Rio  Verde  River,  projected  reservoirs  on, 
344 

Robinson,  Col.  E.  N.,  59-62 

Rock  Creek  reservoir-site,  363,  364 

Rock-fill  dams  : 

Barrett,  Cal.,  32-35 

Bowman,  Cal.,  74,  75 

Castle  wood,  Colo.,  43-47 

Chatsworth  Park,  Cal.,  42-44 

Denver  Water  Company's,  Colo.,  66-70 

East  Canyon  Creek,  Utah,  64-66 

English  dam,  Cal.,  71-73 

Escondido,  Cal.,  2-19,  393 

Lake  Avalon,  N.  M. ,  47-53 

Lake  McMillan,  N.  M..  51,  53-59 

Lower  Otay,  Cal.,  19-33,  393 

Morena.  Cal.,  35-43 

Pecos  Valley,  N.  M.,  47 

Upper  Otay,  Cal.,  41-43,  399 

Walnut  Grove,  Ariz.,  CO-63 

Rubble-concrete,  117 

Run-off,  303.  304  : 

Bear  Valley,  Cal.,  district,  174 
Cuyamaca  watershed,  285 
Rock  Creek  watershed.  363 
Salt  River,  Ariz.,  344 
Sweetwater,  Cal.,  district,  174 

Saguache  state  dam,  Colo.,  297 

Salt  River,  Ariz..  841-344 

San  Andreas  dam,  Cal.,  295 

San  Carlos  reservoir-site,  Ariz.,  330,  391 


INDEX. 


413 


San  Diego  River,  Cal.,  125 
San  Diego  County  reservoir-sites,  372 
San  Elljo  Creels,  Cal.,  2 
San  Joaquin  Electric  Company,  98 
San  Leandro  hydraulic  fill  dam,  77,  400 
San  Luis  Rey  River,  Cal.,  5 
San  Mateo  dam,  Cal.,  189-205 
Sand  Lake  reservoir-site,  Texas,  362 
Santa  Ana  River,  Cal.,  164 
Santa  Fe  Ry.,  storage-reservoirs,  214 
Savage,  H.  N.,  Chief  Engineer  San  Diego 
"  Land  and  Town  Co.,  31,  137,  138,  151 
Sazilly,  M.,  118 

Section,  Walnut  Canyon  dam,  Ariz.,  227 
Sedimentation,  Sweetwater  reservoir,  Cal., 
151 

Self-balanced  gates,  273 
Seligraan  dam,  214,  219-221 
Settlement,  Asbti  dam,  279 
Seymour,  J.  J.,  99 
Sig-dam,  122 
Silt  : 

deposit  of,  151,  250 

Rio  Grande  River,  361 

volume  of,  carried  by  river  Po,  Indus, 

Ganges,  Mississippi,  and  Colorado, 

250 

Siphoning  canal  across  the  Rio  Grande 

River,  359 
Sluicing-head,  76 

volume  of  water  necessary  for,  76 
Sodom,  N.  Y.,  dam,  238 
South  Antelope  Valley  Irrigation  Company, 

Cal.,  299,  301 
South  Fork  reservoir,  Penn.,  73 
South  Platte  dam,  Colo.,  70 
Southern  California  Mountain  Water  Com- 
pany, 19 
Spanish  dams,  118 
Spillway  : 

Bear  Valley  dam,  166 

Denver  Water  Company's  dam,  67 

East  Canyon  Creek  dam,  66 

Heraet  dam,  153 

lack  of,  281 

Lake  Christine  dam,  100 
Lower  Otay  dam,  23 
Seligman  dam,  221 
Sweetwater  dam,  138,  139 
Tyler  dam,  83 
Walnut  Creek  dam,  62 
Spring  Valley  Water-works,  189 


State  dams,  Colo.,  296 
Steel-core  rock-fill  dams  : 

Denvt  r  Water  Company's,  66 

East  Canyon  Creek,  64 

Lower  Otay,  19 
Steel  dam  : 

Ash  Fork,  214,  222-224 

cost  of,  224 

questionable  success  of,  223 
Storage-reservoirs  : 

natural  gravel,  311 

Santa  Fe  Ry.,  214 
Strains,  masonry  dams,  118 
Submerged  dams  : 

Pacoiraa,  205-211 

Kingman,  214-219 
Surveys,  reservoir,  U.  S.  Geolog.  Survey, 

314,  321,  386-389 
Swan  Lake  reservoir-site,  314 
Sweetwater,  California: 

dam,  20,  120,  122,  125,  126-152,  395 

reservoir  distributing  system,  152 
Sweetwater,  Wyo.,  reservoir-site,  315 
Swift  River,  Mass.,  reservoir,  315 

Tables  : 

cost  of  reservoir  construction  per  acre- 
foot,  American  reservoirs,  390  ' 

cost  of  reservoir  construction  per  acre- 
foot,  projected  American  reservoirs, 
391 

cost  of  reservoir  construction  per  acre- 
foot,  foreign  reservoirs ,  391 

reservoir  capacities  and  areas,  392- 
403 

reservoir  capacities,  areas,  watershed 
and  elevation,  from  U.  S.  reservoir 
surveys,  386-389 
Tadini,  M.,  250 
Tamarack  logs,  73,  74 
Tanks  : 

Ceylon,  274 
India,  277 
Tansa  dam,  India,  266 

Temescal  hydraulic-fill  dam,  California,  77 
Tension  in  dams,  122 
Tension  strains,  118 
Ternay  dam,  France,  256,  391 
Tests  concrete  and  masonry  Vyrnwy  dam, 
263 

Tia  Juana  River,  California,  27 
Timber  crib  rock-fill  dam,  74 


414 


INDEX. 


Titicus  dam,  237 
Tlelat  dam,  Algiers,  265 
Tonto  Basin,  Arizona,  dam-  and  reservoir- 
site,  339,  391 
Tower  : 

reservoirs,  362 
Sweetwater  dam,  132 
Tramways  used,  Escondido  dam  construc- 
tion, 8 

Triangular  form  of  dam,  119 
Trass  mortar  used  in  Remscheid  dam  as 
a  substitute  for  Portland  cement,  261 
Tuolumne  River,  CaL,  174 
Turbine  wheels,  at  Folsom  dam,  Cal.,  189 
Turlock  Irrigation  district,  176,  179 
Twin  Lakes  reservoir,  Colo.,  303 
Tyler,  Texas,  hydraulic  dam,  78, '79,  81,  85 
Tytam  dam,  China,  272 

Underground  waters,  rate  of  flow  of,  213, 
302 

Upper  Otay,  Cal.  : 

dam,  41-43 

reservoir,  399 
Upper  Pecos,  reservoir-site,  362 
Utah  Agricultural  Experiment  Station,  116 

Val  de  Infierno  dam,  Spain,  253 

Vallejo  dam,  Cal.,  280 

V  eranum  tank,  India,  277 

Velocity  of  flow  through  sand,  213 

Verdon  dam,  France,  257 

Victor: 

dam  and  reservoir-site,  373-379,  391 

reservoir  capacity,  375-379 

watershed,  374 
Villardam,  Spain,  254,  391 
Vingeanne  dam,  France,  256 
Vischer,  Hubert,  280 
Volume  : 

Agua  Fria  dam,  206 

Little  Bear  reservoir,  371 

masonry.  New  Croton  dam,  237 

of  water  for  sluicing-heads,  76 
Vyrnwy  dam,  Wales,  262,  391 

Wagoner,  Luther,  59,  62.  177 
Walnut  Canyon.  Ariz.,  225 
dam,  214,  225-228 


Walnut  Grove,  Ariz.,  58 

rock-flu  dam,  58-03 
Warner's  ranch  reservoir-site,  San  Luia 

Key  River,  Cal.,  6 
Waste- weir,  131,  238 
Water  cushion,  45 
Water-power,  derricks,  161 
Water  rights,  litigation  over,  293 
Watershed  : 

areas,  392-403 

Barrett,  35 

Bear  Valley,  173 

Chatsworth  dam,  43 

Denver  Water  Company's  reservoir,  71 

Habra,  264 

Hemet,  163 

Little  Bear  Valley,  372 
Morena,  89 

New  Croton,  N.  Y.,  237 
Otay  Creek,  27 
Pecos  River,  54 
Seligman,  222 
Walnut  Canyon,  225 
Water-supply  : 

Lake  McMillan,  57 
Pecos  River,  54 
Rio  Grande  River,  360 
Sante  Fe  Ry.,  214 

sources  in  vicinity  of  San  Diego,  371 
Weather  bureau,  U.  S.  data  on  precipita- 
tion, 57 
Wegmann,  Edward,  118,  247 
Wells,  A.  M.,  45 
Wells,  L.  W.,  84 
Whiting,  J.  E.,  261 
Williams  dam,  Ariz.,  214,  224 
Wilson,  H.  M.,  118,  122,  277,  278 
Wire    ropeway  used   in   construction  of 

Hemet  dam,  161 
Wood  stave  pipe,  90,  235 

used  for  siphoning  canal  across  Rio 
Grande  River,  359 
Wright  law,  2,  19 

Wyoming,  reservoir-sites,  projected  in,  315 

Yellow  pine,  use  of,  for  wood  stave  pipe^ 
359 

Zola  dam,  France,  120,  125,  255 


i 


"mm 


UNIVERSITY  OF  ILLINOIS-UHBANA 


3  0112  069883616 


